How to Learn What Customers Actually Need Before You Build
14 min read · Entrepreneur Scenarios
Kelsey spent three weeks scheduling customer discovery interviews. She had a hypothesis about project management pain points and needed to validate it before building. Ten interviews scheduled with target customers. Questions prepared.
The first interview started well. She asked about their current workflow. They mentioned frustrations. Then, excited by what seemed like validation, Kelsey mentioned her solution: "We're building a tool that solves exactly that!" The prospect lit up. "That sounds amazing! I'd definitely use that."
Kelsey walked away feeling great. Nine more interviews went the same way. Everyone loved it. Six months of building followed. When she came back to sell, nobody bought. They had been polite, not honest. She had taught them to lie to her.
"You can't trust what customers say they'll do in the future. You can only trust how they currently do things."— Rob Fitzpatrick, The Mom Test
Customer discovery is the foundational skill that determines whether you build something people pay for or something that dies in an MVP graveyard. But most founders get it catastrophically wrong. They pitch when they should listen. They ask about the future when they should ask about the past. They leave interviews with false confidence and build the wrong thing.
Why Customer Discovery Is So Hard
The knowledge isn't hard. Everyone knows they should "talk to customers." But executing under pressure is where founders fail. Your nervous system wants validation, not truth. You've invested months in an idea – the last thing you want is someone to say it's not valuable. So you unconsciously bias the conversation.
42%
of startups fail because they build something nobody wants
Source: CB Insights, 2023
6-12 mo
wasted by founders who misunderstood the problem before building
Source: Steve Blank, Customer Development
The gap isn't knowing you should do customer discovery. The gap is resisting the urge to pitch your solution, accepting uncomfortable truths, and digging beneath surface-level answers when your brain wants to move on. This is a psychological challenge disguised as a research task.
The Framework: Past Behavior Over Future Predictions
Customer discovery draws from multiple proven methodologies. Rob Fitzpatrick's "The Mom Test" teaches you to ask about the past, not the future. Steve Blank's Customer Development methodology shows you to get out of the building and test hypotheses like a scientist. Cindy Alvarez's "Lean Customer Development" reveals how to detect real constraints versus wish lists.
The common thread: people lie about what they'll do, but tell the truth about what they've done.
Six Techniques That Work
1. "Tell Me About the Last Time That Happened"
What it is: Ground every question in specific past events instead of hypothetical futures. Ask about workflows, tools used, money spent on the last occurrence of the problem.
Why it works: People give optimistic predictions about the future to be polite. They tell you the truth about past events because those already happened. This reveals constraints, actual costs, and real urgency. (Fitzpatrick, The Mom Test) (Fitzpatrick, The Mom Test)
2. Ask About the Problem, Not Your Solution
What it is: Focus 100% of the conversation on understanding their world. Never mention your product, even when they ask. The moment you pitch, you bias the entire interview.
Why it works: When people know what you're building, they unconsciously tailor their answers to be helpful. You need their unfiltered reality, not their helpful fiction. (Blank, Customer Development) (Blank, Customer Development)
3. "How Are You Solving It Now?"
What it is: Understand their current workarounds, tools, and spend. What they're paying now (in time or money) reveals what they'll pay for a real solution.
Why it works: If someone spends $100/month on a janky workaround, you know they'll pay for a proper solution. If they've never tried to solve it, it's not urgent enough to buy. Current spend is your pricing anchor. (Fitzpatrick, The Mom Test) (Fitzpatrick, The Mom Test)
4. "Why Was This Hard?" (Dig 2-3 Levels Deep)
What it is: Ask "Why?" repeatedly to dig beneath surface complaints. The first answer is always superficial. The third answer reveals the real stakes.
Why it works: People give you the socially acceptable answer first. Digging deeper reveals budget impact, competitive pressure, career risk, or personal pain – the real motivations that drive purchasing decisions. (Alvarez, Lean Customer Development) (Alvarez, Lean Customer Development)
5. Seek Commitment, Not Compliments
What it is: Test whether they'll invest time, money, or reputation – not just praise. Commitment costs something. Compliments are free.
Why it works: "That's a great idea!" means nothing. Real validation comes from sacrifice: introducing you to peers, scheduling follow-ups, pre-ordering, or spending time on prototypes. Absence of commitment reveals absence of urgency. (Fitzpatrick, The Mom Test) (Fitzpatrick, The Mom Test)
6. Interview Recent Buyers, Not Active Shoppers
What it is: Talk to people who recently solved the problem (bought a solution), not people currently researching. Buyers reveal what drives purchase decisions. Shoppers haven't committed yet.
Why it works: People actively shopping haven't made the hard choice. They're exploring, not buying. Recent buyers reveal what tipped them over the edge – that's the insight that predicts future purchases. (LEANFoundry, Common Mistakes) (LEANFoundry, Common Customer Interview Mistakes)
Five Mistakes That Ruin Discovery Interviews
These are the behaviors that produce false positives and waste months of development time:
Pitching Your Solution
The moment you explain your idea, the interview is ruined. They'll tell you what they think you want to hear. Keep the conversation 100% on their problem. If they ask "What are you building?" deflect: "I'm still figuring that out – that's why I'm asking you these questions."
Asking "Would You Buy This?"
Hypothetical questions produce optimistic lies. People say yes to be polite, not because they'll actually buy. Ask about what they've done (past behavior), not what they'd do (future predictions).
Accepting Surface-Level Answers
If they say "It's annoying" and you move on, you've learned nothing. Ask "Why is that a problem?" and "Why does that matter?" at least 2-3 times. The real motivation is buried beneath the first answer.
Talking More Than 40% of the Time
Discovery is about listening, not explaining. If you're doing most of the talking, you're not learning. Ask questions, then be comfortable with silence. Let them fill it.
Accepting "That's Interesting!" as Validation
Enthusiasm without commitment is worthless. Push for something concrete: introductions, time, pre-orders, or willingness to test prototypes. If they won't invest anything, the problem isn't urgent.
How DebateClub Trains This Skill
Everyone's read The Mom Test. But staying disciplined when you're face-to-face with a prospect and desperate for validation is a different challenge entirely. DebateClub gives you a safe place to fail until you build the reflex to stay curious instead of pitching.
The Setup
You enter the customer segment you're targeting, the problem hypothesis you want to test, and how you found this person. The system generates a realistic prospect who has recently dealt with the problem and has tried existing solutions.
The Practice Engine: A Real Example
The Opening
"Hi! Yeah, I got your message. I have about 20 minutes – what did you want to know?"
The prospect is slightly guarded but professional. This is your moment to build rapport and start exploring their world.
Bad Technique
You say:
"Great! So we're building a tool that helps teams collaborate more efficiently. We think it could really solve the issues you're probably facing. Would something like that be useful for you?"
What the system detects:
- •Pitched solution immediately – You explained your idea before understanding their problem
- •Hypothetical question – Asked 'would this be useful' instead of asking about past events
- •Assumed their problems – Said 'issues you're probably facing' without asking
Opponent responds:
"Oh, that does sound interesting! Yeah, we definitely struggle with collaboration. Let me think about it and I'll get back to you."
Result: The prospect gave you polite enthusiasm but no commitment. They'll never follow up. You taught them what you wanted to hear, and they said it. The interview produced zero useful information.
Good Technique
You say:
"Thanks for taking the time! I'm trying to understand how teams like yours handle collaboration. Can you tell me about the last time you had a collaboration breakdown – what happened, and how did you deal with it?"
What the system detects:
- •Past-focused question – Asked about 'last time' instead of hypotheticals
- •Stayed on their problem – No mention of your solution
- •Specific scenario requested – Asked for a concrete story, not abstract opinions
Opponent responds:
"Oh man, yeah. Last week we had a client deliverable that got completely messed up because three people were working on different versions. We ended up manually merging everything at 11 PM the night before the deadline. It was a disaster."
Result: The prospect opened up with a specific, painful story. Now you can dig deeper: What tools were they using? What did that cost them in time? What have they tried to fix it? You're learning real constraints, not polite opinions.
After the Session: Detailed Analysis
Problem Focus
9/10
Kept conversation entirely on their problem. Never mentioned your solution.
Specificity
9/10
Asked about 'last time' – grounded in past events, not hypotheticals.
Discovery Depth
7/10
Got specific story. Could dig deeper with 'why' questions about impact.
Validation Quality
8/10
Avoided seeking compliments. Next step: ask about current solutions and spend.
The system shows exactly where you succeeded and where you can improve. It measures whether you stayed focused on problems, asked about the past, dug beneath surface answers, and sought evidence over enthusiasm.
The AI opponent mirrors real prospect behavior. When you pitch too early, it gets polite and vague. When you ask past-focused questions, it opens up with specific details. When you dig deeper with "why" questions, it reveals layers. It reacts to your technique the way actual customers do, rewarding discipline and punishing unconscious bias.
Opening Scenarios
Each practice session opens with a realistic customer discovery scenario:
"Hi! Yeah, I got your message. I have about 20 minutes – what did you want to know?"
"Hey there. I'm between meetings, but I can chat for a bit. You mentioned wanting to learn about project management workflows?"
"Sure, I can talk. Just so you know, I've done a few of these startup interviews before – are you going to pitch me something?"
Behavioral Rules
The prospect responds to your technique, not just your words:
- If you pitch your solution: The prospect becomes polite but vague, giving enthusiastic lies
- If you ask hypothetical questions: They say "Probably!" or "That sounds useful!" with zero commitment
- If you ask about specific past events: They become detailed, sharing workflows, costs, and real constraints
- If you dig deeper with 'why' questions: They reveal layers: surface complaint → practical impact → real motivation
- If you accept surface answers: They stay superficial – no deeper insights emerge
- If you seek commitment (intros, time, money): They either demonstrate real interest or reveal the problem isn't urgent
What Gets Measured
After each practice session, you receive detailed analysis across four dimensions:
Problem Focus
Did you keep the conversation on their problem, or did you pitch your solution? Measures ability to stay curious about their world.
Specificity
Did you ask about past events ("last time"), or hypothetical futures ("would you")? Measures grounding in actual behavior.
Discovery Depth
Did you dig beneath surface answers with 'why,' or accept the first thing they said? Measures ability to uncover root causes.
Validation Quality
Did you seek concrete evidence (current spend, commitments), or accept enthusiasm? Measures rigor in validation.
What Changes After Practice
After practicing customer discovery across multiple sessions, you will notice:
You stop pitching unconsciously. The urge to explain your solution fades. You stay genuinely curious about their world.
You catch yourself asking hypotheticals. When you start to say "Would you...", you course-correct to "Tell me about the last time..."
You dig deeper automatically. Surface-level answers feel incomplete. You naturally ask "Why does that matter?" until you reach real stakes.
You distinguish real problems from polite interest. You recognize the difference between "That's interesting!" and actual commitment.
The Bottom Line
Kelsey's mistake wasn't conducting customer discovery interviews. Her mistake was pitching her solution and accepting polite enthusiasm as validation. Six months of building wasted because she taught her interviewees to lie to her.
The difference between building what people want and building what dies in an MVP graveyard isn't more interviews – it's better interviews. Past behavior over future predictions. Deep exploration over surface answers. Commitment over compliments.
Practice Customer Discovery
Face realistic prospects. Learn to uncover real needs without pitching. Build the muscle memory to conduct unbiased discovery interviews.
Start PracticingSources & Further Reading
- 1. Fitzpatrick, Rob. (2019). The Mom Test: How to talk to customers & learn if your business is a good idea when everyone is lying to you.
- 2. Blank, Steve. (2013). The Four Steps to the Epiphany. K&S Ranch.
- 3. Alvarez, Cindy. (2014). Lean Customer Development: Building Products Your Customers Will Buy. O'Reilly Media.
- 4. Moore, Geoffrey. (2014). Crossing the Chasm: Marketing and Selling Disruptive Products to Mainstream Customers. HarperBusiness.
- 5. "3 Common Customer Interviewing Mistakes." LEANFoundry. https://www.leanfoundry.com/articles/3-common-customer-interviewing-mistakes