Building Products in the AI & Cloud Era

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Chapter 5: Pricing, Packaging, and Monetization

A price is the one line of a product that every customer reads.

Most teams decide what a product costs at the end, when the thing is built and someone in finance asks what to put on the invoice. By then the important choices have been made, quietly, by people who were not thinking about price at all: which features went into the first release, which customers it was shaped for, which events the system records and which it throws away. This chapter argues for the opposite order. What a product will cost, how it is cut into packages, how its use is counted and billed, and how its price may later change are product decisions in their own right, and they belong at the start, beside the questions of value and usability that Chapter 1 gathered under the four risks. Viability is settled as much by the price as by the product.

The case that has taught the industry most about getting this wrong is small, and it is now 26 years old. In September 2000 Amazon ran a five-day test on 68 DVD titles, in which the discount a customer saw on each title was set at random between 20% and 40%. Customers who talked about DVDs on an online fan forum compared notes and found that the same disc carried different prices for different people at the same moment; Computerworld reported one title at $25.97 in one browser and $23.97 in another. Amazon’s first explanation, that it routinely tested aspects of the site “such as the navigation system, overall site design and product pricing”, satisfied nobody, because a suspicion had already formed that loyal customers were paying more than new ones. Within days the company promised refunds. On 27 September it issued a statement that called the test a mistake that had “created uncertainty and complexity for our customers”. It said it had refunded 6,896 customers an average of $3.10 each, and it made a promise about any future test: every buyer would automatically receive the lowest test price for that item. Jeff Bezos denied that demographics had played any part (“We’ve never tested and we never will test prices based on customer demographics”), and then went further than a denial: “What we did was a random price test, and even that was a mistake because it created uncertainty for customers rather than simplifying their lives.” Figure 5.1 sets the scene and the month that followed it.

Figure 5.1 — Amazon’s DVD price test, September 2000, drawn as a schematic. The disc and the moment were the same and only the price differed; the month ended in the remedy worth copying, that every buyer in a test pays the lowest price tested.

The money was trivial, a little over $21,000 by the arithmetic of Amazon’s own figures. The lesson has lasted, and it has three parts. A price is visible in a way that a button color is not, because customers compare prices with one another and read a difference as a statement about themselves. A random design, which an experimenter rightly regards as the fairest way to assign a treatment, is no defense against the charge of unfairness, since the customer who paid more does not care how the coin was tossed. And the remedy Amazon chose, that everyone in a test pays the lowest price tested, is a rule worth copying, because it turns a price test into a discount test. Andrew Odlyzko discussed the episode in his 2003 paper on privacy, economics and price discrimination on the internet, and it remains the standard example in that literature of how strongly buyers resent being charged differently for the same thing.

Encore meets these questions with Verified Resale, a bet to replace the old Partner Listings links with resale that Encore can vouch for: fans list tickets they bought through the Sale Gate, authorized partners such as Rowmate show those listings to buyers, a screened fan buys, and Encore reissues the ticket under a new barcode. The bet stands or falls on prices that three parties must accept at once. Fans must find the fee worth the certainty. Organizers must see enough control, and enough of the money, to switch resale on. Partners must earn enough to send their buyers. In the months of discovery that Chapter 3 followed, the product trio has to settle the fee, the organizer’s share and the cap, decide which of Encore’s tiers get resale, design the metering that pays organizers their share, and do all of it without ever running the kind of test Amazon apologized for. The chapter takes that work in order, from price before product in Section 5.1 to changing a price in public in Section 5.5.

5.1 Price Before Product

The willingness-to-pay conversation

Madhavan Ramanujam and Georg Tacke, both of the pricing consultancy Simon-Kucher, put the argument of this section into the subtitle of their 2016 book Monetizing Innovation: how smart companies design the product around the price. The book distills a long consulting practice into a simple claim. Most new products fail commercially for reasons that were knowable before anything was built, and the cheapest way to learn them is to talk about price early, while the product is still a concept and every answer can still change its scope. The central instrument is a conversation. A customer’s willingness to pay (WTP) is the highest price at which they would still choose a defined offer over going without it, and the willingness-to-pay conversation is the structured interview that estimates it for a segment before the offer exists.

The order of that conversation matters more than its questions. Ramanujam and Tacke run it from the problem, to the solution, to the value, and only then to the price. A physician taking a history works the same way: first the symptoms, then how they affect the patient’s life, then what the patient has already tried, and only after all that a treatment. Asking about price first is like prescribing before the patient has finished describing the pain. The customer anchors on a number before either side knows what the number is for, and everything said afterwards bends toward defending it. Here the analogy breaks, and the break is the most important thing to know about the method. A patient has every reason to describe the pain honestly. A customer asked about price has a reason to understate it, and even an honest customer is a poor witness to their own future behavior. Jonas Schmidt and Tammo Bijmolt’s meta-analysis of 77 studies, published in 2020, found that stated willingness to pay exceeded real willingness to pay by 21% on average, and by more for expensive and specialized goods.

So the answers from a willingness-to-pay conversation are inputs to scope, recorded as ranges, compared across segments and replaced by behavior whenever behavior can be had: a price charged in a pilot, a letter of intent, an organizer’s signature on a term sheet. The conversation earns its place because it changes what gets built, and the arguments about what to leave out happen before the code exists.

Encore added the price questions to the discovery interviews that Chapter 3 described, with its design-partner organizers and with Rowmate. The organizers were asked first what resale cost them today, in duplicated barcodes turned away at the door and angry fans in their inboxes, then what verified resale would be worth, and only then about money. Most named a share of between 2% and 5% of each resale price as fair, none would pay a fee to have resale switched on, and several said they would switch it on only if they could close it well before doors. Rowmate’s people, asked the same sequence, named three to five points of the resale price as an acceptable commission on capped, verified listings, because verified listings remove the refunds and chargebacks that duplicated barcodes cost them. Fans were not asked at all. The Wizard of Oz pilot of Section 3.2 gave something better than their opinions: at its four shows in Lyon and Antwerp, every resale buyer paid the same 10% fee, shown in the all-in price, and the trio watched what they did. Four shows and about 11,200 tickets could not measure demand, which the pilot read only qualitatively, but they could show whether buyers balked at the fee once the price was real.

Those conversations changed the product. The organizers’ insistence on closing resale before doors became the default resale window, which runs from purchase until two hours before doors. A request from two promoters for a cap above face value was refused in the first month, because the cap is a platform rule that organizers may only tighten, and Section 5.5 shows the law moving the same way, so that nobody designed a console around a control that would never ship. Detailed resale analytics fell down the list when not one organizer said it was worth anything to them.

Four ways to fail

Ramanujam and Tacke name four ways in which new products fail to make money. Feature shock is a product with too many features, priced too high and too hard to explain. A minivation is the right product priced too low, so that it sells well and earns far less than it could. A hidden gem is a potential success that is never brought to market, usually because it sits outside what the company thinks of as its core. And the undead are products that nobody wants, kept alive because nobody is willing to say so. The taxonomy comes from consulting experience and has no independent research behind it, so it is best used as a lens and a shared vocabulary, which is how Encore uses it. Figure 5.2 maps each failure to something in Encore’s own history.

Figure 5.2 — Ramanujam and Tacke’s four failures, each mapped to an Encore product. All four were knowable before launch from a willingness-to-pay conversation that nobody held.

The four names are most useful before a bet is funded, as a way to ask which failure it is most exposed to. Verified Resale’s largest exposure is to the undead. If fans do not trust a reissued ticket, or organizers will not switch resale on, a well-built product will sit unused while the grey market carries on beside it, and the bet’s kill criteria exist to catch exactly that. Its second exposure is feature shock. A rules engine with 40 options, each requested by one organizer in one interview, would be hard to explain, test and sell, so the trio cut the organizer’s controls to the few that the fairness invariants allow: switching resale off, setting the window, lowering the cap and lowering the per-fan limits.

Segments drawn by need

The fifth chapter of Monetizing Innovation warns against defaulting to one offer for everyone, and it proposes segmenting customers by their needs and their willingness to pay before segmenting them by size. Size tells a company how much a customer might spend, while needs tell it what the customer will spend it on, and two customers of the same size may want opposite things from the same feature. Encore’s tiers already segment organizers by size and by the isolation they require, as Section 5.2 will show. Verified Resale needed a second cut.

The interviews revealed two groups of organizers who wanted different things from resale. Control-seeking organizers, many of them festival and tour promoters who had fought touts for years, wanted resale closed until well after the on-sale, low per-fan limits and an early cut-off. Revenue-seeking organizers wanted the widest possible resale window and the largest number of resold tickets, because every one of them pays the organizer three points. A conventional segmentation would offer the second group a higher cap in exchange for a larger fee. Encore cannot, because its rules only tighten: the cap is face value at most, the fee split is fixed, and no organizer may loosen a default. So the two segments pay the same price and receive the same economics, and they differ only in configuration. The console therefore offers three starting presets, “Standard”, which keeps the defaults, “Fan-first”, which tightens the window and the per-fan limits, and “Resale off”, and each can be adjusted within the platform’s limits; in Ireland, where the law forbids it, “Resale off” is not offered (Section 5.5). Segmentation is usually presented as a way to charge different customers different amounts, and here, with the price fixed by principle, it did its work on the product’s defaults instead.

The business case from the outside in

Ramanujam and Tacke ask that the business case for a new product be built from the outside in, starting from validated willingness to pay and the sizes of the segments that showed it. A cost-plus case asks what the product will cost and adds a margin, which tells us what we would like to charge and nothing about whether anyone will pay it. A case built from the outside starts from what customers will pay and asks whether the product can be built and run for less.

Encore’s case for Verified Resale starts from one resold ticket, because every term of the economics is defined per ticket. Take a ticket with a face value of €60, which in Encore’s usage means the original price the seller paid, primary fees included. It resells at face value, the buyer pays a 10% fee on top and the €66 is split as Figure 5.3 shows. Encore’s three points, €1.80, must carry the payment provider’s charges on a €66 payment, fraud losses and the support each resale needs. Against that, the variable cost of serving one more ticket on Encore’s platform is €0.12, the figure the Resilience book derives in its Section 2.5. That is the marginal cost, and the right one for a case about additional tickets; the blended €0.16 includes fixed costs that resale does not change. The Wizard of Oz pilot measured the remaining large term directly: with every reissue done by hand through Support’s lost-ticket replacement screen, agents spent a median of 14 minutes on each completed resale, falling from 26 at the first show to nine at the fourth (Figure 3.5). Even nine minutes of an agent’s time costs several times what Encore’s three points could pay for, and the case therefore rests on an explicit condition: once reissue is automated, support per resale must fall to a fraction of the pilot’s figure, or the product loses money on every ticket it sells.

The case reduces the bet’s economics to a few things that must become true, each with a number attached and each testable before full launch: organizers switching resale on for enough events, partners bringing enough buyers that listings sell before doors, and support per resale falling far enough. The Software book’s Section 8.5 computes the contribution margin per resold ticket once real data exists, and it finds what the pilot already hinted at: the cost of a dispute decides the margin far more than the level of the fee.

Saying what the price buys

The tenth chapter of Monetizing Innovation is titled “The Innovation Won’t Speak for Itself”, and its argument is that value must be explained in the customer’s terms, by the people who sell and by the product itself. For each of Encore’s three parties the value is different, and so is the message. Organizers are offered control and a share of the money, and the fee is barely mentioned to them, since they never pay it. The console shows, event by event, how many tickets were resold through Verified Resale and what the organizer’s three points have earned, so that the value accumulates where the organizer can see it. Fans are offered a ticket that will scan at the door, at no more than its face value, and the 10% fee is presented as the price of that certainty, inside an all-in price shown from the first screen, beside the Verified badge that the Design System team built and the reissue status that tells both buyer and seller where their ticket stands. Partners are offered inventory they can sell without fearing that it is fake, and a commission on every ticket their buyers take. Each message describes something the product actually does, which is the test a value message must pass.

Recap. Price belongs at the start because willingness to pay changes what is worth building, but stated willingness runs well above real willingness, so its answers are ranges that shape scope until behavior replaces them. The four failures are a vocabulary for asking where a bet is exposed, and needs-based segments shape a product’s configuration even when the price is fixed. A business case built from the outside in reduces a bet to a few conditions that must become true.

Exercise 5.1. Choose one item on your roadmap that has not been built yet. Ask three customers, in the order problem, solution, value and price, what they would pay for it, and record each answer as a range. Then write down how the answers change the item’s scope: what you would now leave out, what you would add, and which answer you would most like to replace with observed behavior.

5.2 Business Models

Five models and the behavior each rewards

A business model, for our purposes, is the rule by which a product turns use into revenue, and every such rule rewards some behavior over others. Ramanujam and Tacke describe five monetization models. In a subscription, the customer pays a recurring price for continued access, which rewards the company for keeping customers and makes revenue predictable. In dynamic pricing, the price moves with demand, which invites the suspicion that the seller is exploiting demand. In market-based pricing, the price is discovered by bidding, as in an auction. In pay-as-you-go, the customer pays per unit of use, which ties the company’s revenue to the customer’s success. And in freemium, a basic version is free and a premium version is paid, which rewards converting free users.

Encore uses two of the five. Its software-as-a-service (SaaS) tiers for venues and organizers are subscriptions, and its per-ticket fees are pay-as-you-go. The self-service tier has no subscription at all and pays only through per-ticket fees, which makes it pay-as-you-go as well; it is not freemium, because every ticket sold pays. The three models Encore does not use were declined deliberately. Encore runs no dynamic pricing of its own, for reasons Section 5.5 gives. Resale is not market-based, since bidding under a ceiling of face value would be a queue in disguise. And nothing is given away, because every ticket sold on the platform costs something to serve. A model is a choice of incentives that outlasts the reasons for it: a company that charges per ticket comes to care about volume above everything, one that charges a subscription comes to care about renewal, and Encore, running both, has to keep each revenue line’s incentives visible so that one does not quietly distort the other.

Per-ticket fees and the all-in price

The per-ticket service fee that fans pay on primary sales funds Encore’s marketplace. It scales with demand, and it is the part of Encore’s pricing that the most people see. In the European Union (EU) it is also regulated, and it is worth being precise about where the rules come from, because they are often misattributed. The duty to show the all-in price, the total a consumer will pay including every unavoidable fee and tax, comes from the Consumer Rights Directive of 2011, whose Article 6(1)(e) requires the trader to give “the total price of the goods or services inclusive of taxes” and all additional charges before the consumer is bound. Leaving a material charge out of the price is a misleading omission under the Unfair Commercial Practices Directive of 2005. The Omnibus Directive of 2019, which Member States had to apply from 28 May 2022, did not invent all-in pricing. What it added was sharper enforcement, requiring that the maximum fine for widespread infringements be at least 4% of the trader’s annual turnover, or at least €2 million where turnover is unknown, together with several new duties that Section 5.5 meets.

The practice that the rules forbid has a name. Drip pricing is showing a headline price and adding unavoidable charges later in the purchase, one step at a time, so that the customer has committed time and attention before seeing the real total. The United Kingdom (UK), where Encore does not sell, banned drip pricing outright from 6 April 2025 under its Digital Markets, Competition and Consumers Act 2024, which shows which way the law is moving. Encore shows the all-in price from the first screen on which any price appears, for primary tickets and resale alike. How that price is rendered across locales and currencies is a design-system concern, and Section 7.5 treats it there.

What a venue pays for

The Architecture book’s Section 14.5 has already priced Encore’s tiers from the engineering side, and its Figure 14.4 pairs each tier with a deployment model, an isolation level and an objective. Self-service venues share a pool in serverless cells of about 50 and a single 99.9% objective. Professional tenants run in Kubernetes cells with a database each and an error budget of their own. The Enterprise tenant has a silo, and for it the isolation is the product. This section adds the commercial logic that the tier sheet leaves implicit: what a buyer pays for at each tier, and what makes a buyer move up.

Self-service venues pay a per-ticket platform fee, netted from their payouts, and no monthly subscription. Professional tenants pay a monthly subscription and a lower per-ticket fee. Enterprise terms are negotiated once a year. The structure creates three reasons to upgrade, and Encore designs each one on purpose. The first is volume. Because the professional subscription is paired with a lower per-ticket fee, there is a crossover point, a number of tickets a month, above which Professional costs less in total than Self-service, and the console tells a self-service venue when it has passed that point. The second is isolation. A venue that does not want its customer lists in tables shared with a rival’s, or that wants an error budget no other tenant can spend, needs Professional, because only Professional provides them. The third is the enterprise checklist, from single sign-on to customer-managed keys, which the Architecture book showed to be a list of architectural commitments. An upgrade path can also be built from annoyance, from limits set low enough to irritate a customer into paying, and it produces upgrades and churn together, because the customer remembers the irritation. Each of Encore’s three triggers corresponds to a real difference in what the platform does or costs to run, which is why the company can explain all three without embarrassment.

Pricing the resale fee

Section 2.3 established that pricing in a multi-sided market is set for all sides together, and that the real question is who pays. David Evans and Richard Schmalensee, in Matchmakers (2016), describe the usual answer: platforms often charge one side little or nothing, because that side is the harder one to attract and its presence is what the other side pays for, and they recover the cost from the side that values the match more. Geoffrey Parker, Marshall Van Alstyne and Sangeet Paul Choudary make a similar case in the monetization chapter of Platform Revolution (2016). For Verified Resale the scarce side is the seller. A resale market is only as good as its listings, and a fan who cannot attend has the easy alternative of handing the ticket to a friend or selling it on the grey market. So sellers pay nothing and receive the resale price in full. Buyers, who came looking for a ticket that will scan, pay the fee.

The trio compared three structures for that fee. A flat fee per ticket is simple to explain and to account for, but it falls hardest on cheap tickets: a €5 fee is a quarter of a €20 club ticket and a fortieth of a €200 stadium ticket. A percentage of the resale price scales with the ticket and divides cleanly among the parties. A third structure, in which the rate falls as the resale price drops below face value, would spare sellers who are already taking a loss, but under a face-value cap prices can only fall, a percentage already shrinks in euros as they do, and a sliding rate would complicate the price display and the ledger for a small benefit. Encore chose a fixed 10% of the resale price, charged to the buyer and shown in the all-in price. The split is fixed as well, at four points to the partner that brought the buyer, three to the organizer and three to Encore, whose share carries the payment provider’s charges, fraud losses and support. A listing is visible in Encore’s own app and on every authorized partner, and when the buyer purchases in Encore’s app there is no partner to pay, so Encore keeps those four points as well. Figure 5.3 follows one resale through each case.

Figure 5.3 — One resale at face value, three ways. The 10% fee is split four, three and three points; Encore keeps the partner’s four points when the buyer purchases in its own app. Where the law caps what the buyer pays, as for Ireland’s designated events, the fee comes out of the seller’s proceeds. The seller is paid five days after the event.

The cap needs one more sentence of definition, because the law cares about it. The resale price may not exceed the original price the seller paid, including the primary fees on that purchase, and the buyer’s 10% fee is charged on top. That is Encore’s default in every market. Where the law caps the buyer’s total, as Ireland’s Sale of Tickets Act 2021 does for designated events, the fee is taken from the seller’s proceeds instead, which is the third row of the figure. The split is the same in every case, and it is the same for every organizer, on every tier, whatever they negotiate elsewhere. Organizers may tighten the rules of resale, but the money has one rule, because a split that varies by contract would turn every payout into a special case and every partner statement into a negotiation.

One question about the fee belongs to finance, and the product must be ready for either answer. When a buyer pays €66, the payment provider sends €60 to the seller and €6 to Encore, and Encore pays €4.20 of that fee on to the partner and the organizer. Is Encore’s revenue €66, €6 or €1.80? Under International Financial Reporting Standard (IFRS) 15, the accounting standard for revenue, the answer turns on whether Encore acts as principal, controlling the ticket before it passes to the buyer, or as agent, arranging a sale between others; its guidance on that distinction sits in paragraphs B34 to B38. Encore’s finance team makes that judgment. The product’s obligation is to record each party’s share separately, on every resale, so that either answer can be reported without reconstructing anything.

Metrics follow the model

Alistair Croll and Benjamin Yoskovitz organize much of Lean Analytics (2013) around one question, what business are you in, because the business model decides which numbers matter. Section 4.1 drew the general lesson, that model and stage drive the choice of metric. Here we need only the mapping for Encore’s three revenue lines, which Figure 5.4 gives.

Figure 5.4 — Each revenue line brings its own measures. The dashboards of Section 4.1 follow from this table; contribution margin per resold ticket is computed in the Software book’s Section 8.5.

One of these terms needs a definition, and one of the incentives a warning. Take rate is the share of the value of transactions that a platform keeps as revenue. For Verified Resale, measured against the resale price, it is three points when a partner brings the buyer and seven when the buyer purchases in Encore’s app. That difference is where the model’s incentive becomes dangerous. A team judged on take rate alone would have every reason to steer buyers toward Encore’s app and away from the partners who brought the market liquidity in the first place, and the partners would notice. Encore guards against this by policy: every listing appears everywhere at the same all-in price, partners see their own channel’s numbers, and the Resale team’s dashboard puts partner-sourced sales beside take rate, so that nobody can improve one by quietly damaging the other.

Recap. Each monetization model rewards some behavior, and Encore runs two of the five deliberately, declining the others for reasons it can state. All-in pricing comes from the Consumer Rights and Unfair Commercial Practices Directives, and venue tiers carry upgrade triggers that follow real differences in value and cost. The resale fee is a fixed 10% on the buyer, split four, three and three, with a clear rule where the law caps the buyer’s total, and the model chosen decides the metrics, which must be watched beside the relationships they could damage.

Exercise 5.2. List your product’s revenue lines. For each, write down which of the five models it uses, which customer behavior that model rewards, and which behavior it rewards inside your own company. Then find one place where two of your revenue lines reward conflicting behavior, and say who in your organization is responsible for noticing.

5.3 Packaging into Tiers

Leaders, fillers and killers

A tier is a named package of features, limits and terms sold at one price, and the familiar arrangement of three tiers, often called good, better and best, is the commonest way to offer different segments different value without negotiating with each customer. The hard part is deciding what goes where. Ramanujam and Tacke sort features into three kinds. Leaders are the must-have features with the highest willingness to pay, the ones that decide which tier a customer chooses. Fillers are nice-to-haves that add perceived value without driving the choice. Killers are features most buyers would refuse to pay for, and forcing them into a package can sink the sale of the whole package. A tier is well designed when each one is built around a leader, carries fillers where they cost little, and contains no killers.

Packaging is older than software, and one of its earliest theorists saw its uncomfortable side clearly. The French engineer and economist Jules Dupuit, writing in 1849 about tolls on transport, observed that railway companies left their third-class carriages open to the weather, and that the reason was not the cost of a roof. It was to keep travelers who could afford second class from traveling third. Dupuit had described what pricing people now call a fence, a difference between packages that stops customers with a high willingness to pay from buying the cheaper one. The analogy teaches, and it also warns. A fence built from deliberate damage works, but it insults everyone on the cheap side of it, and they remember. Software makes deliberate damage easy, because withholding a feature costs nothing to build. The fences that last are built from real differences, in isolation, scale, support or cost to serve, which the customer on either side can accept as fair. Encore’s tiers follow that principle, as the tier sheet in the Architecture book shows: what separates them is a pool, a database of one’s own and a silo, each with a real cost behind it.

Verified Resale forced a packaging decision. Putting resale only in Professional and Enterprise looked like a leader, a reason to upgrade, and the trio rejected it for three reasons. Resale’s fairness rules are platform rules, which hold for every event whatever its organizer pays, and selling fairness by tier would mean that the fans of small venues stayed on the grey market. Liquidity needs breadth, because a resale market that covers only the events of larger tenants gives partners too few listings to build a habit around. And in Ireland the law makes resale at or below face value impossible to forbid, so for Irish events a tier gate would have been unenforceable. Verified Resale is therefore available on every tier, and the organizer’s three-point share is paid on all of them. What differs by tier is a filler, the detailed resale reports in Organizer Insights, which come with Professional. A mandatory resale analytics pack priced into the self-service tier was considered and dropped, because for a venue selling a few hundred tickets a month it would have been a killer.

Bundles, add-ons and conjoint

Once features are sorted, a second choice remains: which to include in a tier and which to sell separately. The working rule is that a feature belongs in the bundle when most of the tier’s segment values it, and in an add-on when a minority values it highly and the rest would resent paying for it. Where the stakes justify it, the choice can be measured. Conjoint analysis is a survey method in which respondents choose repeatedly between packages that differ in features and price, and the pattern of their choices reveals how much each feature is worth to them. Its roots are in the theory of conjoint measurement that R. Duncan Luce and John Tukey published in 1964, and Paul Green carried it into marketing in the early 1970s; Green, Abba Krieger and Jerry Wind looked back on three decades of its use in 2001. It is a mature method, and it has the same weakness as every survey of hypothetical money. Schmidt and Bijmolt found hypothetical bias in indirect methods such as conjoint as well as in direct questions, so a conjoint study’s results are checked against real sales before anyone trusts them.

Encore reserves conjoint studies for its tier sheet, which it revisits once a year and where a misplaced feature affects every tenant’s renewal. Verified Resale did not need one, because the one packaging question it left open, where the detailed reports belong, was small enough to settle from the interviews.

Entitlements in code

Packaging is a commercial decision, and it should be possible to change it without changing code. That is only true if the code never mentions a tier. An entitlement is a named right that a customer holds under its plan, such as a feature, a limit or a quota, recorded as data. A tier, seen from the code, is simply a set of entitlements, versioned and given an effective date, and product code checks the entitlement it needs and never the tier’s name. A plan file in Encore’s form looks like this:

plan: professional
version: 7
effective_from: 2027-01-01        # rated and billed from this date
entitlements:
  features: [verified_resale, resale_rules_console, resale_reports_detailed, own_database]
  limits:
    staff_seats: 50
  quotas:
    rule_assistant_requests_per_month: 2000
# product code asks:   entitlements.allows(tenant, "resale_reports_detailed")
# product code never asks:   tenant.tier == "professional"

The rule matters for a reason of complexity, in the sense the Architecture book took from Brooks. The packaging of a business is essential complexity: Encore really does sell different things to different customers, and no design removes that. A tier name tested in a hundred places across 40 teams is accidental complexity, added by us, and its cost appears the first time packaging changes. Moving one feature to every tier then becomes a code change in every service that tested the name, released on every team’s schedule. When code checks entitlements instead, the same move is one edit to versioned data, reviewed and rolled out like any other configuration.

The Software book’s Section 7.3 builds the entitlements service, chooses how it fails (open for display, closed for anything involving money) and rolls entitlement changes out per tenant, and the same section explains why entitlements, release flags and configuration must be kept apart. Each entitlement is also covered by a contract test, of the kind the Software book’s Section 3.3 describes, which checks that a tenant without it cannot reach the feature by any path.

Packaging cannot outrun the architecture

The Architecture book’s Section 14.5 states the principle that packaging and architecture must be designed together, and this chapter needs only one rule to put it into practice: every promise made to a customer must correspond to a cell of the tier sheet. A promise the deployment model cannot deliver is a debt that engineering pays later, usually during an incident.

The commonest form of the mistake is an objective sold to a tenant whose tier cannot honor it. Suppose a large self-service venue, negotiating hard, is promised 99.95% availability. Its tier runs in a shared pool with one error budget spent by about 50 venues together, and nothing about that venue’s contract changes how the pool behaves. The promise can be kept only by luck, or by quietly moving the venue to a professional cell at Encore’s expense, and neither is a plan. Encore’s rule is that any commitment in a proposal that does not appear on the tier sheet goes to the Tenant Configuration team and the relevant product trio before signature, and the answer is either a different tier or a refusal.

Recap. Good tiers are built around leaders, contain no killers, and are separated by fences built from real differences. Verified Resale is on every tier because its fairness rules, its liquidity and Irish law all demand breadth. Packaging lives in code as entitlements held as data, so that it can change without code changes, and no customer may be promised anything the tier sheet cannot deliver.

Exercise 5.3. Find three places in a codebase you know that test a plan or tier name directly. Rewrite one of them as an entitlement check, and write down what packaging change the original code would have turned into a release across several teams.

5.4 Metering and Billing as Software

Billing systems have unforgiving users. A customer will forgive a slow page sooner than an invoice that charges them twice, and the practices of this section are correspondingly conservative, and old. In 1494 Luca Pacioli set out double-entry bookkeeping in his Summa de arithmetica, describing the Venetian merchants’ method of recording every amount twice, as a debit in one account and a credit in another, so that the books must balance and an error shows itself as an imbalance. Five centuries later, the same principle runs through every serious billing system: record each fact once, derive everything else from the facts, and arrange matters so that a mistake cannot hide.

Billable events are facts

Metering starts with an event. A usage event is a record that something billable happened, written once by the domain in which it happened and carrying a key that makes a second write of the same fact harmless. That last property is idempotency, and it matters because in a distributed system every message may arrive twice. If the fact carries a key derived from what happened, the receiver can recognize the repeat and ignore it, and the meter counts each sale once however many times it is told about it. Stripe’s application programming interface (API) documentation explains the practice for payment requests, and Brandur Leach’s 2017 essay on implementing Stripe-like idempotency keys in Postgres shows how to build it.

For Verified Resale the billable fact is ResaleCompleted, and its timing is a product decision. A listing moves through listed, reserved, sold and reissued, the lifecycle the Software book’s Section 8.2 describes, and the tempting moment to bill is the sale. Encore bills at the reissue instead. The Resale service emits ResaleCompleted only after the Inventory team’s issuance code has revoked the seller’s barcode and issued the buyer’s, so a sale whose reissue fails is never billed, and nobody has to unwind a charge for a ticket that never changed hands. Two later moments are kept separate from it, because they answer different questions. The seller is paid five days after the event, when the reissued ticket can no longer be disputed, and the partner’s commission, accrued at the sale, is released at the same moment and reversed if the sale is reversed, as the Software book’s Section 8.3 describes. The event looks like this:

{
  "type": "ResaleCompleted",
  "idempotency_key": "resale:lst_88412:reissue:1",
  "occurred_at": "2027-03-14T19:02:11Z",
  "tenant_id": "tnt_4471",
  "event_id": "evt_20931",
  "listing_id": "lst_88412",
  "channel": "rowmate",
  "resale_price": { "amount": 6000, "currency": "EUR" },
  "fee_payer": "buyer",
  "revoked_ticket_id": "tkt_5513c",
  "issued_ticket_id": "tkt_9f02a"
}

The event carries the facts and none of the money. It does not say what the fee was or how it was split, because those depend on the price book, and the price book can change. fee_payer records which rule applied, buyer or seller, because that is a fact about where this sale took place. Metering then aggregates these events per tenant, as the Architecture book’s Section 14.5 describes for every other per-tenant resource.

Rating against the price in force

Rating is the step that turns usage into money, by applying to each event the price that was in force when the event happened. That clause is where most billing errors are born. A price book that holds only current prices cannot rate last month’s usage correctly once anything has changed, and it cannot reproduce last month’s invoice when a customer disputes it. So every price, fee rate, split and cap in Encore’s price book carries two dates. Its valid-from date says when it applies to the world, and its recorded-at date says when Encore wrote it down. Martin Fowler’s essays on temporal patterns gave this arrangement its common vocabulary, and the two-date form is usually called bitemporal. The first date lets the rating engine find the right price for any event. The second lets anyone ask what Encore knew when it issued a given invoice, so that a late correction is visible as one.

price_book: verified-resale
entry: resale-fee
valid_from: 2027-01-01
recorded_at: 2026-10-02T09:14:00Z
fee_rate: 0.10                    # of the resale price
split: { partner: 0.04, organizer: 0.03, encore: 0.03 }
split_own_app: { organizer: 0.03, encore: 0.07 }
fee_payer_rule: buyer, except where local law caps the buyer's total

With facts in the events and prices in the book, invoices and payout statements become derived documents. Each can be recomputed at any time from the events and the price book as they stood, and if the recomputation disagrees with what was sent, something is wrong and can be found. The organizer’s three points become a payout line, the partner’s four points a line on its monthly statement, and every split is written to the finance ledger that the Architecture book’s Section 9.1 separated from orders, where it is reconciled daily. The money itself never passes through Encore’s hands. Resale payments run through the primary payment provider’s split-payment product, which holds the seller’s €60 in an account in the seller’s name until the payout date and sends the €6 fee to Encore; Encore then pays the organizer’s and the partner’s shares out of its fee. Why Encore must never hold the buyer’s money, and how it moves, is the subject of the Software book’s Section 8.2. Figure 5.5 follows one resale from its lifecycle to the documents derived from it.

Figure 5.5 — Facts in the event, prices in the book. Billing starts at the reissue, not the sale; every payout and statement line is derived from a rated ResaleCompleted, and four nightly checks make sure nothing is counted twice, missed or rated at the wrong price.

When payment fails

Payments fail for ordinary reasons. Dunning is the sequence of retries, notices and grace periods by which a company tries to collect a failed payment before it restricts service. It is standard practice, and the published statistics about how much revenue it recovers come almost entirely from billing vendors’ marketing, so they are best left unquoted. What matters for a product team is the policy, because the policy decides how a customer is treated on a bad day.

Encore’s policy follows its tiers. Self-service venues have nothing to dun, because their fees are netted from their payouts, which is one quiet advantage of pay-as-you-go; only a venue whose refunds exceed its sales in a period ends up owing money, and it is invoiced. Professional subscriptions are retried over 14 days with a notice at the first failure, another at a week and a third at two weeks, and the tenant then has a grace period to day 30. After that, a person in Billing & Payouts reviews the account with its commercial owner, and only a person may decide to suspend. Enterprise payments follow the contract and are never handled by automation at all.

A concert explains why. Imagine a promoter and a venue falling out over money on the night of a show. Any sensible house settles the dispute after the show, and nobody cuts the power during the encore, because the audience is not a party to the dispute. Encore’s version is that a suspended organizer’s fans are never harmed and that no on-sale is ever stopped without a person’s decision. The analogy breaks in a way that makes the rule more urgent for software. Cutting the power at a concert requires someone to walk to a switch in front of thousands of witnesses, while a scheduled job can suspend a tenant at three in the morning with nobody watching. So suspension is a state that only a person can enter. How it works without collateral damage, with sold tickets staying valid and payouts held, is the subject of the Software book’s Section 7.5.

Every line traces to an event

Billing has a short list of correctness properties, and each can be checked. Every invoice and payout line must trace back to the events that produced it. No event may be counted twice, and none may be missed. The parts of every amount must add up to the whole. The billing system’s totals must match the finance ledger’s every day. And every change to a price, a split or a contract must leave a record of who made it and when. None of these is specific to Encore; they are what billing systems everywhere have learned to check, usually after failing to.

The most instructive public failure is a recent one. In May 2017 Uber disclosed that in New York City it had been taking its commission from drivers on the gross fare, which included taxes and the Black Car Fund fee, where it should have used the net fare. The company said the error came to light while it was overhauling driver receipts, and committed to repay drivers what they were owed, plus interest; the Wall Street Journal estimated the total at about $45 million. Nothing about the payments themselves was broken. The formula was applied to the wrong base on every trip, and nothing checked the base against the agreement. The positive proof of the practice comes from Stripe, which in 2024 described Ledger, its internal system for tracking and validating money movement: an immutable, double-entry-style log that checks fund flows across about 5 billion events a day.

Encore runs four checks every night. Every ResaleCompleted must have exactly one rated line, and every rated line one event. Every resale’s parts must sum to what the buyer paid, so that €66 is exactly €60 to the seller and the three shares of the fee. The day’s splits in the billing system must equal the day’s entries in the finance ledger. And the price book entry applied to each line must be the one valid on the event’s date. In platform work inside a large bank I learned to distrust any number that could not be recomputed from its inputs, and these checks exist so that every number Encore pays out can be.

Build the meter, buy the invoice

Billing engines are mature products, and the Architecture book’s Chapter 13 gives the test for buying one: buy what is commodity, and build what differentiates the business or encodes knowledge nobody else has. Invoicing, tax calculation, payment collection and the mechanics of dunning are commodity, and Encore buys them for its subscriptions. Collecting and splitting resale payments is bought as well, from the primary payment provider, and Encore accepts the price of that choice: only that provider carries resale, so resale checkout pauses when it is degraded. The metering events and the revenue-share logic are Encore’s own, because no vendor knows that a resale is billed at reissue, that a partner’s four points move to Encore when the buyer purchases in the app, or that an Irish designated event takes the fee from the seller. Encore owns ResaleCompleted, the price book and the rating of resale fees, and hands the bought engine the subscription lines it has to invoice.

Recap. Billable usage is recorded as facts, once, with idempotency keys, by the domain where it happens, and Encore bills resale at reissue so that a failed reissue is never charged. Rating applies the price in force when the usage happened, from a bitemporal price book, which makes every invoice and payout reproducible. Dunning is a product policy in which only a person may suspend a customer, and correctness is a short list of checks run every day.

Exercise 5.4. Take one line of a real invoice your company has sent and trace it back to the usage events that produced it. Note every place along the way where a number could be counted twice or computed on the wrong base, and say which of them a nightly check would catch.

5.5 Changing Prices Safely

Price integrity

A price is a promise to everyone who might pay it, and like any promise it is valuable only if it holds. Price integrity is the property that a company’s prices mean the same thing to every customer and change only through announced, dated rules. Ramanujam and Tacke give it a chapter, warning against knee-jerk repricing: discounts granted quietly to whoever complains, increases sprung without notice. Each such move teaches customers that the price is negotiable for those who push.

Netflix provided the canonical case of a price change without integrity’s protections. On 12 July 2011 it split its DVD and streaming services into separate plans, so that customers who had both saw their monthly price rise from $9.99 to $15.98, about 60%. New members paid the new prices at once, and every existing member moved to them on 1 September, seven weeks later, with no grandfathering. The reaction was fierce. On 18 September Reed Hastings apologized in a blog post and in the same post announced that the DVD business would be renamed Qwikster; on 10 October Netflix dropped Qwikster, but kept the new prices. On 24 October it reported that it had lost 800,000 US subscribers in the third quarter, leaving 23.8 million, against a forecast loss of 600,000. Netflix later recovered and grew far beyond its size in 2011, and the episode is remembered for its method more than its price: a large change imposed on every existing customer at once, with short notice and no path between the old price and the new.

The protection most companies now use is grandfathering: existing customers keep their old price for a stated period after a change, and the period ends on a published date, its sunset. Without a sunset, grandfathering slowly fills the billing system with prices nobody can explain. At Encore the price book is published, existing tenants keep old terms until a stated sunset, and discounts are granted only under written rules.

Price tests and their ethics

Amazon’s DVD test returns here, because it marks the limit of what experimentation may do with a price. Online controlled experiments, the subject of Section 4.3, are the most reliable tool a product team has, and the temptation to point them at prices is strong. Ron Kohavi, Diane Tang and Ya Xu give a chapter of Trustworthy Online Controlled Experiments (2020) to the ethics of experiments, weighing risk against benefit and asking when participants must consent, and on a price those questions are sharper than anywhere else, because a price test changes what a person pays.

Three rules have emerged from practice, and Encore adopts all of them. Test packaging and presentation before price, since how an offer is described and bundled often matters more than its level, and testing it harms nobody. Test prices on new offers and new customers, never on what an existing customer already buys. And when a price is tested, everyone in the test pays the lowest price tested, Amazon’s own remedy, which makes the test a discount for some and a loss for nobody.

The law has drawn a line of its own, and it is narrower than many people assume. The Omnibus Directive added a duty to the Consumer Rights Directive, in its Article 6(1)(ea), to tell consumers “where applicable, that the price was personalised on the basis of automated decision-making”. Its Recital 45 is explicit about what that duty does not cover: it “should not apply to techniques such as ‘dynamic’ or ‘real-time’ pricing that involve changing the price in a highly flexible and quick manner in response to market demands when those techniques do not involve personalisation based on automated decision-making.” So the Directive governs prices set for a person from what is known about them, and leaves demand-based pricing and randomized price tests outside its disclosure duty. Randomized tests sit in a grey zone, because they are not personalized on any characteristic of the consumer, and where personal data drives a decision, the General Data Protection Regulation’s Article 22 on automated decisions applies as well. The practice the duty targets is real. The European Commission’s 2018 study of personalized pricing and offers found that 61% of the 160 websites it mystery-shopped personalized the ranking of the offers they showed.

Encore’s rule is stricter than the law, and it is absolute: no individual price experiments on fans, ever. Geographic and switchback designs, which Section 4.5 describes, may vary what a fan sees or when something happens, but never the price that a given fan pays. When Encore tests how the resale fee is displayed, as Chapter 10 recounts, every fan in every arm pays the same 10%, and only the presentation moves. The rule costs Encore some knowledge about price sensitivity, and the trio accepts that cost knowingly, because Verified Resale’s whole proposition rests on fans believing that a price at Encore is the same for everyone.

Moving prices and public trust

Dynamic pricing is setting a price that moves with demand, often automatically and within minutes, and in concert ticketing it has drawn more public anger than any other pricing practice. The case most often cited in Europe turned out, on investigation, to be about something else. When tickets for Oasis’s reunion tour went on sale in the UK in August 2024, many fans believed they had been charged surge prices by an algorithm. The Competition and Markets Authority (CMA) opened an investigation into Ticketmaster in September 2024 and closed it with undertakings on 25 September 2025. It found that many fans believed dynamic pricing had been used, and stated that “the CMA has not found evidence that this was the case.” What it did find was tiered pricing that fans in the queue had not been told about, with standing tickets sold at two prices and the higher released once the cheaper had sold out, and “platinum” tickets sold at almost two and a half times the price of standard tickets without any extra benefit being explained.

Ticketmaster undertook, without admitting wrongdoing or liability, to give at least 24 hours’ notice when it would use tiered pricing, to show price ranges in queues and update them quickly as cheaper tickets sold out, to avoid misleading labels, and to report to the CMA for two years. The CMA’s chief executive, Sarah Cardell, put the principle in one sentence: “Fans who spend their hard-earned money to see artists they love deserve to see clear, accurate information, upfront.” Fans can accept prices that move. What they will not accept is a price that moves without their being told how.

Encore’s position follows directly. The organizer sets the prices, through the price levels and ticket types that the Pricing & Presales team’s tools provide, and Encore displays them truthfully. If an organizer releases a price level in stages, the event page says so before the on-sale and the waiting room shows the current range. Encore runs no algorithmic surge of its own. One more rule from the Omnibus Directive bears on the same screens: when a price reduction is announced, the prior price shown must be the lowest price of the previous 30 days, under the new Article 6a of the Price Indication Directive, so that an organizer’s price-drop promotion cannot inflate the price it claims to cut.

Resale rules by country

There is no EU-wide cap on resale prices. The one EU-wide rule specific to ticket resale is the point the Omnibus Directive added to the blacklist of unfair practices, point 23a of Annex I of the Unfair Commercial Practices Directive: reselling event tickets to consumers is always unfair “if the trader acquired them by using automated means to circumvent any limit imposed on the number of tickets that a person can buy”. The Directive’s Recital 50 leaves Member States free to go further, and several have, Belgium and Ireland among them. Ireland’s law is the most precise, and it shows what a resale rule asks of a product.

The Sale of Tickets (Cultural, Entertainment, Recreational and Sporting Events) Act 2021 was signed on 14 July 2021 and fully commenced on 31 July. Its cap is narrower than its reputation. Section 15 makes it an offence for a secondary seller to sell or advertise a ticket above the original sale price, but only for events in a designated venue and for designated events, designated on application by the venue operator or organizer under sections 7 to 9; designation is aimed mainly at venues with a capacity of 1,000 or more. By July 2022, 27 venues and 42 events had been designated, Croke Park and the Aviva Stadium among them. The “original sale price” includes “any additional charge or fee applying to the sale”, which is why Encore takes the resale fee from the seller for these events. Two further provisions matter as much as the cap. Section 17 requires secondary sellers to state the original price and the seat or standing area, and requires operators of secondary marketplaces to make sure their listings carry that information. And section 19, which applies to every event, designated or not, makes void any term of a primary sale that excludes or limits transferring a ticket for nothing or reselling it at or below the original price, unless the term is justified by safety, public health or public order. An organizer may forbid resale above face value. An organizer may not forbid resale at or below it. Encore’s console therefore offers Irish organizers a lower cap, a resale window and per-fan limits, and no switch to turn resale off.

The UK’s long dispute with viagogo shows where regulators actually spend their effort. After an investigation that the Office of Fair Trading began in 2012 and the CMA took up in 2016, the High Court made an order on 27 November 2018 requiring viagogo to tell buyers the seat they would get, the risk that a ticket might be refused at the door and who the seller was, to stop misleading claims about availability and how fast tickets were selling, and to honor its guarantee. In March 2019 the CMA said viagogo was still not compliant; on 4 July 2019 it moved forward with contempt proceedings, and on 5 September 2019 it suspended them after viagogo addressed the outstanding concerns. The whole case concerned what a marketplace shows its buyers, and the same concern runs through Ireland’s section 17 and the Omnibus Directive’s requirement that online marketplaces tell consumers whether the seller is a trader. A resale cap is one rule among many, and the larger engineering requirement is that every listing carries its original price including fees, its seat or standing area and its seller’s status.

The UK is now moving further, and Encore watches it as context, since it does not sell there. On 19 November 2025 the government announced that resale above face value would become illegal, with face value defined as the original price plus unavoidable fees, a cap on resale platforms’ service fees “to prevent the price limit being undermined”, and fines of up to 10% of global turnover. The King’s Speech of 13 May 2026 promised a draft Ticket Tout Ban Bill for scrutiny. As this chapter is written, in October 2026, the cap has been announced and is not yet law. The design consequence for Encore is that rules arrive by country, change on dates set by legislatures, and sometimes cover the fee as well as the price. Figure 5.6 shows the shape of the configuration that follows.

Figure 5.6 — Resale rules by scope. Platform and legal rules form a ceiling that organizers may lower but never raise; the configuration is versioned like the price book, so every past resale can be checked against the rules in force on its day.

Rolling out a price change

The best recent proof of how not to change a price comes from Unity. On 12 September 2023 the company announced a Runtime Fee, a charge per installation of games built with its engine, which would apply to games that were already shipped and selling, so that businesses planned under one unit of charge were moved to another after the fact. Developers objected loudly, and on 22 September, ten days later, Unity apologized and withdrew much of it, exempting games already made with current versions of the engine. In September 2024 its new chief executive, Matt Bromberg, wrote that “we’ve made the decision to cancel the Runtime Fee for our games customers, effective immediately,” and Unity replaced it with seat price increases from 1 January 2025: 8% for Pro and 25% for Enterprise, while the revenue ceiling of the free Personal tier doubled from $100,000 to $200,000. The replacement changed the level of a familiar price, where the Runtime Fee had changed what was counted and applied the change to decisions customers had already made. Unity’s customers accepted the higher seat prices, and the change to the unit of charge was the one Unity had to withdraw.

Encore’s sequence for any price change has five steps. The change is announced to the affected customers with its effective date, well before that date. The price book gains a new version with that valid-from date, so that rating switches cleanly and nothing old is rewritten. Existing customers are grandfathered to a stated sunset. Support receives the announcement, the reasons and the answers to the questions that will come, before the customers do. And the guardrail metrics of Section 4.1, which for organizers include churn and the rate at which they switch resale off, are watched through the change and for a quarter after it. The unit of charge never changes retroactively. A change is recorded in a short form that lives beside the price book entry it creates:

change: professional-subscription-2027
affects: plan professional, versions 6 to 7
announced: 2026-10-01             # to every affected tenant, in the console and by email
effective_from: 2027-01-01        # new tenants and renewals
grandfathered_until: 2027-06-30   # existing tenants keep version 6 terms until then
unit_of_charge_changed: false     # if true, the change needs the trio's sign-off and a full year's notice
support_briefed: 2026-09-24
guardrails: [professional churn, downgrade rate, resale disabled rate, support contacts]
owner: Billing & Payouts with the Tenant Configuration trio

The configuration side of the change, the new price book version reaching every service that reads it, travels in stages from internal tenants to a few friendly ones to all, with automatic rollback on a health signal, as the Resilience book’s Section 4.3 and the Software book’s Section 7.3, on rolling out configuration, describe. The commercial sequence and the technical one meet at the effective date, so that on the day a price changes, nobody is surprised.

Recap. Prices change only by announced, dated rules, with grandfathering that ends on a published sunset, and the unit of charge never changes retroactively. Price tests vary presentation before price and give everyone the lowest price tested, while Encore forbids individual price experiments on fans outright. Fans resent undisclosed price movements more than moving prices, so Encore shows every tier and change truthfully, and resale rules, which arrive by country, demand above all that every listing discloses what the buyer is getting.

Exercise 5.5. Draft the announcement and the grandfathering rules for a 10% price increase on your product’s middle tier. State the effective date, the sunset, what support will be told and when, and the guardrail metrics you will watch for a quarter. Then ask whether any part of the change alters what you count, and if so, rewrite the plan.

Kata: The Seat and the Meter

Your brief: “Sumwise.” Sumwise sells bookkeeping software to small shops in four EU countries: about 41,000 customers, from single-owner boutiques to bakeries with three branches, served by 70 engineers in eight teams. It has always charged per user seat, at €12, €25 and €45 a month across three tiers, but most shops have one or two users, so revenue barely grows when a customer does. Its costs, meanwhile, follow volume: bank-feed connections, receipt scanning and invoice sending are charged to Sumwise per item by its suppliers, and its heaviest 5% of customers generate over half those costs while paying the same seat price as everyone else. The board wants usage-based pricing by the next financial year. The founders fear a revolt from loyal small customers, sales has granted about 3,000 private discounts nobody can fully list, and the billing code tests the tier name in 140 places.

Deliverables:

1. Willingness-to-pay findings — A plan for the problem, solution, value and price conversation with three segments of your choosing, drawn by need, and the scope decisions you expect the answers to change. Say how you will discount for hypothetical bias and which behavior you will use to check the answers.
2. The price model — The unit of charge, the model it belongs to and the behavior it rewards, with a worked example for a small customer and a heavy one. Show that a typical small shop pays no more than today.
3. Tier sheet with entitlements — Three tiers built around leaders, with fillers and no killers, the fences between them and the real difference behind each fence, and the plan files that express each tier as entitlements.
4. Metering design — The billable events, where each is recorded, its idempotency key, and the bitemporal price book entry that rates it, with the nightly checks that tie Sumwise’s own counts to the supplier invoices.
5. Migration plan — The announcement, the effective date, the grandfathering rules and sunset for existing customers, the treatment of the 3,000 private discounts, the support briefing and the guardrails you will watch.
6. Test policy — What Sumwise may test about the new pricing, on whom, and under what rule about the price each tested customer finally pays.

Rubric:

Where you now stand

You can now treat price as a product decision that comes before construction, find out what customers will pay without believing everything they say, and choose a business model knowing which behavior it will reward. You can package a product so that the fences between tiers are fair and the code never knows a tier’s name, record billable usage as facts and rate them against the price in force, and change a price in public without repeating the mistakes of Amazon, Netflix and Unity. With these decisions Part I’s question, what to build, has its answer. Part II asks how the thing we decided to build should meet the people who use it. Chapter 6 takes up design for people, where Verified Resale’s three faces, the organizer’s console, the buyer’s flow and the seller’s dying barcode, each have to make a fair price and a firm rule understandable at a glance.

References

• Madhavan Ramanujam, Georg Tacke — Monetizing Innovation: How Smart Companies Design the Product Around the Price. Wiley, 2016.
• Amazon.com — Amazon.com Issues Statement Regarding Random Price Testing. Press release, 27 September 2000 — free online.
• European Parliament and Council — Directive (EU) 2019/2161 (the Omnibus Directive). Official Journal of the European Union, 2019 — free online.
• Government of Ireland — Sale of Tickets (Cultural, Entertainment, Recreational and Sporting Events) Act 2021. Irish Statute Book, 2021 — free online.
• Competition and Markets Authority — Secondary ticketing websites. Case page, 2016–2021 — free online.
• Competition and Markets Authority — CMA secures changes from Ticketmaster following Oasis tickets investigation. Press release, 25 September 2025 — free online.
• David S. Evans, Richard Schmalensee — Matchmakers: The New Economics of Multisided Platforms. Harvard Business Review Press, 2016.
• Geoffrey G. Parker, Marshall W. Van Alstyne, Sangeet Paul Choudary — Platform Revolution. W. W. Norton, 2016.
• Alistair Croll, Benjamin Yoskovitz — Lean Analytics. O’Reilly, 2013.
• Jonas Schmidt, Tammo H. A. Bijmolt — Accurately measuring willingness to pay for consumer goods: a meta-analysis of the hypothetical bias. Journal of the Academy of Marketing Science 48(3), 2020 — free online.
• Ron Kohavi, Diane Tang, Ya Xu — Trustworthy Online Controlled Experiments. Cambridge University Press, 2020.
• Tod Golding — Building Multi-Tenant SaaS Architectures. O’Reilly, 2024.
• Ilya Ganelin — Ledger: Stripe’s system for tracking and validating money movement. Stripe, 2024 — free online.
• UK Government — Government bans ticket touting to protect fans from rip-off prices. Press release, 19 November 2025 — free online.
• Andrew Odlyzko — Privacy, Economics, and Price Discrimination on the Internet. Proceedings of ICEC 2003, ACM, 2003 — free online.
• European Commission — Consumer market study on online market segmentation through personalised pricing/offers in the European Union. European Commission, 2018 — free online.