Free customer interview diagnostic

Can your customer interview survive a friendly conversation?

The Bestie Test shows whether your questions uncover real behavior—or mostly collect compliments, opinions, and polite promises.

8 scenarios · instant score · no signup

What it checks

1

Neutrality

Keep the conversation from turning into a pitch or approval exercise.

2

Past behavior

Anchor learning in real events, actions, and current workarounds.

3

Evidence depth

Follow pain into frequency, consequence, cost, and constraints.

4

Commitment

End with a proportionate next step that tests seriousness.

This tests interviewing choices—not your idea. Only real customer behavior and commitments can create market evidence.

Customer interview guide

A strong customer interview starts before the pitch

Ask about a recent event before showing the idea. Compliments, feature requests, and answers to “would you use it?” describe a reaction to the conversation. They do not tell you what someone did, paid, delayed, or changed when the problem occurred.

Leading customer interview questions and evidence-first replacements
Question to replaceWhy it misleadsAsk this instead
“Do you like this idea?”Tests the reaction to your pitch and invites politeness.“Tell me about the last time this problem happened.”
“Would you pay for this?”Asks for a prediction without a real tradeoff.“What have you paid for or tried to solve it?”
“What features would you want?”Turns the interviewee into the product designer.“Walk me through how you handle it today.”
“Is this problem urgent?”Collects an opinion instead of observable consequences.“What happened the last time it was postponed?”

What counts as customer evidence?

Evidence connects a defined customer to a specific event and a consequence. Listen for the sequence of what happened, the workaround they used, the time or money involved, the people who affected the decision, and what made them act or wait.

  • A recent example with details that can be checked
  • A workaround, purchase, delay, or failed attempt
  • A cost, risk, missed result, or competing priority
  • A decision process with constraints and other people involved
  • A next commitment proportionate to the product stage

Why call it The Bestie Test?

The name tests whether your interview method still works in a friendly conversation. A friend may want to encourage you, but a stranger can be polite too. The relationship is not the deciding factor; the quality of the evidence is.

“Great idea” is encouragement. “I used a spreadsheet three times last week, lost four hours, and have budget approval this month” is evidence you can examine.

Use this test when

You are preparing discovery calls, reviewing interview notes, or unsure whether recent conversations produced evidence or approval.

What the score cannot prove

It does not prove demand, price, market size, or product-market fit. The score assesses your choices; customer behavior and commitments test the business.

After the score

Run the next interview

Take The Bestie Test

Customer Truth Lab

Turn one interview into an evidence board and a next experiment.

Open

Customer Interview Script

Prepare questions about recent behavior, constraints, and current workarounds.

Open

Customer Interview Gym

Practice an interview before speaking with a customer.

Open

Customer interview questions, answered

What questions should I avoid in customer interviews?

Avoid questions that ask people to predict future behavior, approve your idea, design features, or agree that a problem is important. Ask for a recent example instead: what happened, what they did, what it cost, and who was involved in the decision.

Are customer compliments evidence of demand?

No. A compliment tells you how someone reacted to the conversation. Demand evidence comes from behavior: repeated attempts to solve the problem, money or time already spent, a costly consequence, or a commitment that matches the stage of your product.

Should I interview friends about my startup idea?

Friends can help you learn if you ask about events they actually experienced and avoid pitching. Their support for you can make praise especially unreliable, so separate warmth toward you from evidence about the problem. Interviewing people outside your network is still important when they better match the buyer you want to serve.

What counts as customer validation?

Validation is evidence that the problem and proposed exchange are real for a defined customer. Strong signals include a current workaround, a budget or decision process, access to relevant data, a scheduled next step, a pilot, a deposit, or a purchase. The right commitment depends on how mature the product is.