How to Run a Customer Interview That Produces Useful Answers

Customer interviews are the cheapest way to find out whether a business idea, a new product or a change to an existing service is worth pursuing. They are also easy to get wrong. Ask people what they think of your idea and most will be kind. Kindness feels encouraging and tells you almost nothing.

The fix is simple: ask about what people have actually done, not what they say they would do.

Who to interview

• People who have the problem you want to solve, ideally recently.
• A mix of current customers, former customers and people who chose a competitor.
• Not friends and family, unless they genuinely fit the profile and you can keep the conversation neutral.

Ten to fifteen interviews with the right people usually reveal the main patterns. Stop when you keep hearing the same things.

Ask about the past, not the future

"Would you use an app that does X?" invites a polite guess. "Tell me about the last time you had to do X" invites a story with real details. Good questions include:

• "When did this last happen? Walk me through what you did."
• "What was the hardest part?"
• "What have you tried to solve it? What did that cost?"
• "What happened in the end?"
• "How often does this come up?"
• "Who else is involved in deciding how to handle it?"

Rob Fitzpatrick's book The Mom Test is built around this principle and is a short, practical read if you want to go deeper.

What to avoid

• Pitching. The moment you describe your solution, the interview becomes a sales meeting and people respond to you rather than their problem. Save the pitch for the end, if at all.
• Leading questions: "Wouldn't it be great if...?"
• Hypotheticals: "How much would you pay for...?" People are poor predictors of their own future spending.
• Talking too much. If you are speaking more than a third of the time, slow down.

Listen for evidence of commitment

Strong signals that a problem is worth solving include:

• They have already spent money or significant time trying to fix it.
• They built their own workaround, such as a spreadsheet or a manual routine.
• They can describe the cost of the problem in money or hours.
• They ask when your solution will be ready, or offer to pay for early access.

Compliments ("That sounds really useful!") are not evidence. A follow-up meeting with their manager, a deposit or a pilot agreement is.

Running the session

1. Keep it short: 20 to 30 minutes respects people's time and keeps focus.
2. Explain the purpose: you are learning, not selling.
3. Ask permission to take notes or record, and explain how you will use them.
4. Follow the energy: when someone becomes animated, ask "Tell me more about that."
5. End with two questions: "Is there anything I should have asked?" and "Who else should I talk to?"

Turn interviews into decisions

Write up each interview the same day, using the same headings: context, current solution, pain points, costs, quotes, signals of commitment. After every five interviews, look for patterns. Note what surprised you; surprises are where the learning is.

Then update your assumptions. If you are working from a one-page business plan, mark which sections the interviews confirmed and which they contradicted, and change the plan accordingly.