Chapter 5 of 9

Chapter 5: Behavioral Economics & Smoke Testing

Measuring revealed preferences through landing pages and "fake doors".

Playbook Chapters
What You'll Learn By the end of this chapter, you'll understand why actions beat words, how to run smoke tests and fake door experiments, and how to design experiments that generate real evidence of demand.

Actions Speak Louder Than Words

When someone says "I'd buy that," they're giving you an opinion. When they actually try to buy it, they're giving you evidence.

Economists call this the difference between Stated Preference (what people say) and Revealed Preference (what people do). For validation, only revealed preference counts.

Stated Preference

"I would definitely use an app that does X."

Reality: People are polite. They want to be helpful. They have no skin in the game. This tells you almost nothing.

Revealed Preference

Person clicks "Pre-order for $99" and enters credit card info.

Reality: They had to overcome friction. They risked something. This is real signal.

The Currency of Validation

The only valid currency is Skin in the Game: time, money, or reputation. If someone isn't willing to invest at least one of these, their "interest" is meaningless.

Smoke Tests: The "Fake Door" Method

A smoke test offers a product that doesn't fully exist yet to see if anyone tries to buy it. It's the ultimate test of desirability.

Landing Page Test

Create a simple page describing your value prop. Drive traffic via ads. Measure clicks on "Sign Up" or "Buy Now."

Cost: $50-500 in ads
Timeline: 1-2 weeks

Concierge MVP

Manually perform the service your software will automate. Zappos started by manually buying shoes from stores.

Cost: Your time
Timeline: Ongoing

Wizard of Oz

Users interact with a frontend that looks finished, but humans do the work behind the scenes.

Cost: Basic UI + manual work
Timeline: 2-4 weeks

Ethical Fake Doors

When running fake door tests, treat users with respect. If they click "Buy," tell them you're in beta or taking early signups—never charge their card without delivering. Offer a discount for launch as thanks for their interest.

Designing Your Experiment

Every experiment needs a clear hypothesis and success criteria—defined before you run it.

The Experiment Template

We believe that [target audience]

will [take this action]

for [this reason/value prop].

We'll know we're right if [metric] reaches [threshold] within [timeframe].

Example: "We believe that freelance designers will pre-order our cash flow tool ($29/month) because they're frustrated with unpredictable income. We'll know we're right if 50 people sign up in 2 weeks from $200 in Facebook ads."

The CTA Strength Ladder

The strength of your evidence depends on the friction of your call-to-action:

CTA Friction Signal Strength
"Learn More" Very Low Weak
"Sign up for updates" Low Moderate
"Join waitlist" (with email) Medium Good
"Pre-order for $X" (credit card) High Strong
Pro Tip: Maximize Friction

Counter-intuitively, you want more friction in your test. A "Learn More" click means almost nothing. A credit card entry (even if you don't charge) is strong evidence of real intent.

What You Walk Away With

  • Revealed Preference Data: Evidence of what people actually do, not just say.
  • Conversion Metrics: Real numbers from your smoke test.
  • Validated (or Invalidated) Demand: Proof that people will take action for your solution.
  • Experiment Artifacts: Landing pages, ad copy, and results for your Lean Vault.
Design Your Smoke Test

Create landing page tests, concierge MVPs, and fake door experiments with our Market Signal Tester.

Market Signal Tester
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Works Cited & Recommended Reading
Lean Startup & Innovation Accounting
Assumption Mapping & Testing
  • 7. Invest in Winning Ideas with Assumption Mapping. Miro
  • 10. Testing Business Ideas: Book Summary. Strategyzer
  • 11. Innovation Tools – The Assumption Mapper. Nico Eggert
  • 14. Business Testing: Is your Hypothesis Really Validated? Strategyzer
  • 16. An Introduction to Assumptions Mapping. Mural
  • 17. Assumption Mapping Techniques. Medium
Customer Interviews & The Mom Test
  • 8. Book Summary: The Mom Test by Rob Fitzpatrick. Medium
  • 22. The Mom Test for Better Customer Interviews. Looppanel
  • 23. The Mom Test by Rob Fitzpatrick [Actionable Summary]. Durmonski.com
  • 9. How to Evaluate Customer Validation in Early Stages. Golden Egg Check
Jobs-to-Be-Done Framework
  • 24. Jobs to be Done 101: Your Interviewing Style Primer. Dscout
  • 25. How To Get Results From Jobs-to-be-Done Interviews. Jobs-to-be-Done
  • 26. A Script to Kickstart JTBD Interviews. JTBD.info
Product-Market Fit & Surveys
  • 33. Sean Ellis Product Market Fit Survey Template. Zonka Feedback
  • 34. How to Use the Product/Market Fit Survey. Lean B2B
  • 35. Product Market-Fit Questions: Tips and Examples. Qualaroo
  • 36. Product/Market Fit Survey by Sean Ellis. PMF Survey
Pricing Validation Methods
Smoke Tests & Fake Door Testing
  • 43. Smoke Tests in Market Research - Complete Guide. Horizon
  • 45. Fake Door Testing - How it Works, Benefits & Risks. Chameleon.io
  • 52. High Hurdle Product Experiment. Learning Loop
  • 53. Fake Door Testing: Measuring User Interest. UXtweak
Conversion Benchmarks & Metrics
  • 46. Landing Page Statistics 2025: 97+ Stats. Marketing LTB
  • 47. Understanding Landing Page Conversion Rates 2025. Nudge
  • 49. What Is A Good Waitlist Conversion Rate? ScaleMath
  • 54. Average Ad Click Through Rates (CTRs). Smart Insights
Decision Making & Kill Criteria
  • 57. From Test Results to Business Decisions. M Accelerator
  • 58. Kill Criteria for Product Managers. Medium
  • 59. When to Kill Your Venture - Session Recap. Bundl

This playbook synthesizes research from Lean Startup methodology, Jobs-to-Be-Done theory, behavioral economics, and validation frameworks. Some book links may be affiliate links.