Founders

How to Measure Willingness to Pay Before You Ship

Antonio Evans8 min read

A person at a laptop reviews a four-question price survey while a second screen shows a buy button leading to a coming soon page and a printed pre-order receipt sits on the desk.
Key points

Key points

  1. 1A Van Westendorp survey narrows down an acceptable price range, but it only records what people say, not what they do.
  2. 2A fake door test measures how many people click a buy button, yet clicks show curiosity more than a willingness to pay.
  3. 3A pre-sale is the only test where money changes hands, so treat it as the strongest evidence of real demand.
  4. 4Read every result conservatively and adjust for the gap between stated intent and actual buying behavior.

Why stated intent overstates real demand

Every method in this protocol that relies on questions carries a known bias. When people estimate what they would pay in a hypothetical setting, the figure runs well above what they actually pay in a choice-based experiment that includes simulated payment. One study found the hypothetical estimate came out about three times higher than the real one, as summarized by OpinionX. That single number should shape how you read every survey result you collect.

The practical consequence is simple. A survey tells you the shape of the market's price perception. A pre-sale tells you whether the market will part with money. You need both, in that order, and you should never let the survey answer override the pre-sale answer when they disagree.

It also helps to know what a good price decision is worth. Pricing is one of the strongest levers a business has; a small improvement in price can lift operating profit far more than a comparable change in volume, a point Chargebee cites from an old Harvard Business Review study. That is the reason to run real tests rather than guess, even though testing takes a few weeks.

Set the ground rules before you test

Three rules keep the tests honest.

Recruit real buyers, not colleagues or fans. People who already like you, or who will never open their wallet, distort every metric. Recruit from the same segment you plan to sell to, and make sure they have the problem your product solves. Salesforce's guide to value-based pricing recommends segmenting your market by industry, company size, location or need, then interviewing representatives from each group. Do the same for test recruitment.

Never ask the direct question. "How much would you pay?" is close to useless. People lowball it to nudge you toward a lower price, or they answer from emotion with no real anchor. The Price Sensitivity Meter was built specifically to avoid that failure by asking about price perceptions around a product rather than a single figure, per the method's overview on Wikipedia. A presentation from POCTRN is blunter: direct questioning is "generally meaningless," and laddering questions ("Would you buy at $10? What about $8?") should not be used at all (POCTRN PDF).

Decide the pass threshold before you run. Write down the click rate, the pre-sale conversion or the revenue figure that would justify building. Koji's fake door guide makes this an explicit step: a click rate only means something relative to a threshold you set in advance. Deciding after you see the data is how teams talk themselves into shipping.

Step 1: Run a Van Westendorp survey to find the acceptable range

The Van Westendorp Price Sensitivity Meter, introduced by Dutch economist Peter van Westendorp in 1976, asks four questions about price perception. Each respondent answers all four, and you plot the results as four cumulative curves, per Wikipedia. Here is the standard wording, adapted from SurveyMonkey's walkthrough and Quantilope's question examples:

  1. At what price would the product be so expensive that you would not consider buying it? (Too expensive)
  2. At what price would it be so cheap that you would question the quality? (Too cheap)
  3. At what price does it start to get expensive, so you would have to think about it, but it is not out of the question? (Expensive)
  4. At what price would it be a bargain, a great buy for the money? (Cheap)

Design the survey

Show respondents a clear description of the product before the questions. Quantilope recommends setting the stage with a product outline so people can visualize what they are pricing. Use open numeric fields rather than preset price buckets; forcing respondents to pick from a list loses precision.

Recruit enough respondents that the curves are stable. The method was originally used with small samples in interviews and focus groups, per POCTRN, but larger samples give smoother distributions. If your buyers split into very different segments, run the analysis separately for each one.

Read the four intersections

Plot cumulative frequencies for each question. Invert the "too cheap" and "cheap" curves so all four can cross, then read these points, per Conjointly's tool documentation:

IntersectionNameWhat it tells you
Too cheap and expensivePoint of marginal cheapness (PMC)Lower bound of the acceptable range
Cheap and too expensivePoint of marginal expensiveness (PME)Upper bound of the acceptable range
Cheap and expensiveIndifference price point (IPP)Where equal numbers call it cheap or expensive
Too cheap and too expensiveOptimal price point (OPP)Where the fewest reject it at either end

For a worked example, Conjointly shows a chart where the acceptable range runs from $5 to $10 with an "optimal" price of $6.75 (Conjointly). Treat that optimal point as a center of gravity, not a recommendation. The whole chart is the output; a single number pulled from it is a fiction.

Add a purchase-intent extension

The basic meter tells you perception, not demand. The Newton, Miller and Smith extension adds two follow-up questions about how likely the respondent is to buy at the expensive and cheap prices, which lets you model a rough revenue curve, per Wikipedia and Sawtooth Software. Without this step the survey cannot say anything about volume, and volume is what decides whether a price is profitable. A high Price Sensitivity count is not the same as a profitable price; POCTRN's deck makes the point that higher volume is not necessarily higher profit.

Know the limits

The method assumes respondents can imagine a pricing landscape and that price is an intrinsic signal of value (Wikipedia). It works best when the product is new enough that no strong reference price exists, per Sawtooth. For products in a mature category with clear comparables, monadic pricing questions or conjoint analysis usually give better answers, Sawtooth and Conjointly both note. And remember the hypothetical bias: the numbers come out high compared with real choices.

Step 2: Run a fake door test to measure clicks on a buy button

A fake door test (also called a painted door test) shows users a real-looking entry point, such as a button, a menu item or a pricing tier, that does not lead to a working feature yet. You measure who clicks and how many try to use it, per Koji's guide. The reason to run one is straightforward: a large share of software features go unused. The Standish Group's CHAOS research put rarely or never used features at 64%, and a later Pendo analysis put the figure at 80%, both cited in Koji's guide.

Design the test

  • Build a convincing entry point. For a pricing test, that means a real buy button with a real price on it, not a vague "Learn more."
  • Instrument the click. Track who clicks, from which segment, and how often. Koji lists click-through rate as the headline metric, with segment, repeat intent and opt-in rate as the supporting signals.
  • Be honest at the door. Show a clear "coming soon" message the moment someone clicks, and offer a real way to be notified. Userpilot is direct about the risk: clicks measure curiosity, not commitment, and a badly handled reveal damages trust.
  • Do not stack tests on the same people. Userpilot recommends spacing tests at least six months apart per user segment so people do not keep hitting dead ends.

What data to collect

Capture four numbers per price point or segment: the share of exposed users who clicked, the repeat click rate, the opt-in rate (how many left an email for early access), and the distribution of clicks by segment. A price that draws clicks from one segment and none from another changes your business case, so split the data.

Read it conservatively

A click is not a purchase. Userpilot warns that a click does not prove someone would change their workflow, pay more or use the product consistently. Apply a discount factor to your click rate when you build a forecast, and treat the opt-in rate as the more meaningful number because it costs the user a small commitment. Koji's guide also flags the method's biggest weakness: a door tells you how many people want something, not why, so follow up with the clickers (Koji).

Step 3: Run a pre-sale to see who actually pays

The pre-sale is the closest you can get to the real market without shipping. Someone enters card details, gets charged, or gets a formal reservation that commits real money. Everything before this step is an estimate; this step is behavior.

Design it the same way you would design the real purchase. Show the actual price, the actual terms, the actual delivery date you can meet. If you are discounting for early commitment, state that plainly and set a deadline. Then collect three things: how many qualified visitors placed an order, how many of those paid versus abandoned at the payment step, and how much revenue the orders represent.

Interpret it as a floor, not a ceiling. A pre-sale confirms demand at your price, but it often comes from your warmest audience, so it will not tell you how a cold market behaves. It also tells you nothing about long-term retention, which for subscription products matters more than the first payment. A customer's lifetime value shapes what you can afford to spend to acquire them, so model a conservative retention assumption alongside the pre-sale data (Pragmatic Institute).

If the pre-sale fails and the survey passed, the pre-sale wins. Do not rationalize a weak pre-sale by pointing to a good survey; that is the exact gap the hypothetical bias predicts.

How the three methods compare

MethodWhat it measuresCost and timeMain biasBest for
Van Westendorp surveyPerceived acceptable price rangeModerate, a few weeksStated intent runs highNew products with no clear reference price
Fake door testClick interest at a shown priceLow, days to weeksClicks show curiosity, not paymentFeatures where prototyping is expensive
Pre-saleActual paymentModerate, needs a working checkoutWarm audience skews resultsFinal go or no-go before building

Read them together as a ladder. The survey tells you where to point. The door tells you whether the price catches anyone's eye. The pre-sale tells you whether anyone will pay. A result that survives all three is as close to evidence as you will get before you ship. Koji's guide frames it well: build the cheapest experiment that generates real evidence, then decide.

Common ways teams fool themselves

  • Leading with the price. Showing a price before describing the product drags every answer toward cheap. Describe the value first, then ask.
  • Quoting the optimal price as a recommendation. The OPP is one intersection on a chart, not a mandate (Conjointly).
  • Counting clicks as demand. Without a discount, a fake door will overstate what people will pay.
  • Citing a competitor's price as your answer. Competitor and cost-plus pricing both ignore what buyers actually value, Maxio's pricing guide lays out why value-based pricing, despite being more research-intensive, is worth the effort.
  • Pricing on one metric and calling it done. A single value metric decouples price from value for customers who get very different value per unit, Robin Landy's analysis explains the risk and points to using a second metric or add-ons as a lever.
FAQ

FAQ

How many people do I need for a Van Westendorp survey?

There is no strict minimum, but small samples produce jagged curves. The method was designed to work in interviews and focus groups (POCTRN), but aim for enough per segment that the four lines cross cleanly. If your buyers split into different segments, segment the sample and the analysis.

Why is asking "how much would you pay?" a bad idea?

People lowball deliberately to push your price down, and many genuinely do not know. Hypothetical estimates have run about three times higher than real willingness to pay in a simulated-payment experiment (OpinionX). The Van Westendorp approach sidesteps this by asking about price perception rather than a direct figure.

Is a fake door test unethical?

It can be, if handled carelessly. The rule is to measure intent and never waste it: show a honest "coming soon" message at the click, offer a real notification option, and do not repeat tests on the same users too often (Koji, Userpilot). A well-run test leaves users feeling heard rather than tricked.

What if my survey and my pre-sale disagree?

Trust the pre-sale. It reflects real money changing hands, while the survey reflects stated intent, which is known to run high. Treat the survey as a way to choose which price points to test, and the pre-sale as the verdict.

Which method should I run first, and which last?

Run the survey first to narrow the range, then the fake door at a price inside that range, then the pre-sale at your chosen price. Each step is cheaper than the next and filters the population of interested buyers. The pre-sale comes last because it is the most expensive to set up and the most meaningful.

Sources

Sources

  1. Van Westendorp for Pricing Research (Survey Guide) - OpinionX
  2. SaaS Pricing And Value Metrics - Lessons From The Top Seeds
  3. Value-Based Pricing: A Complete Overview & Guide - Salesforce
  4. Van Westendorp's Price Sensitivity Meter - Wikipedia
  5. PDF Van Westendorp's Price Sensitivity Meter | POCTRN
  6. Fake Door Testing (Painted Door Test): Validate Demand Before You ...
  7. How To Use The Van Westendorp Price Sensitivity Meter
  8. Van Westendorp Price Sensitivity Meter Questions - Quantilope
  9. Van Westendorp Price Sensitivity Meter Tool Online - Conjointly
  10. Van Westendorp Pricing Model: Definition, How It Works, Examples ...
  11. Is Fake Door Testing Still Worth Doing in The Vibe-Coding Era? - Userpilot
  12. SaaS Pricing: How to Price Software Products - Pragmatic Institute
  13. Guide to SaaS Pricing Models: Strategies and Best Practices - Maxio
  14. The problems with relying on a single value metric to determine SaaS ...
About the author

About the author

Antonio Evans
Antonio Evans

Antonio Evans is the founder of Quanta Intelligence and a fractional CTO who builds HIPAA-ready AI systems for health and life-science companies. Before that he was technical co-founder of FriendsEAT for twenty years, CEO of Socialdraft, and a data engineer at IBM. Antonio lives with his dog Santino in Lisbon, Portugal.

All articles