Customer Interview Questions: 40 Questions in Six Stages, With Why to Ask Each

The first two minutes

Say who you are, why you are calling and how long it will take. Say plainly that you are not selling anything today. Then ask if you may record the call or take notes.

Recording rules differ by state. Federal law allows recording when one party to the conversation consents⁵. Illinois requires the consent of all parties to surreptitiously record a private conversation⁶, and California requires all parties’ consent to record a confidential communication⁷. Ask for consent at the start and record it; if anyone refuses, take notes by hand.

Probing stems

When an answer is vague, use a short stem and wait:

• “What happened next?”
• “Can you show me?”
• “What did that cost you?”
• “What did you do about it?”
• “When was the last time?”
• “Who else was involved?”

“Why” on its own tends to produce a justification. A stem about the next event produces another fact.

The order

Go from broad to narrow: start with the last time it happened, work through pains, current tools and the decision, and leave price and commitment for the end. Broad questions first keep you from steering the person toward the problem you hope they have.

Treat the 40 questions as a bank to pick from. Reading them aloud in order turns the call into a survey. Pick the stages that fit the person, and let the answers decide which follow-ups you use.

The last time it happened

1. When did the problem last come up? Why: it fixes one dated event, so the answers that follow describe something that happened.
2. Walk me through that day, from the start. Why: a story shows steps people skip when they summarize.
3. What were you trying to get done then? This names the goal the problem blocked.
4. What did you do first? Why: the first move shows the default fix and how urgent it felt.
5. Where did it slow down or stop? Why: it points to the exact step a product would replace.
6. How did it end? Why: an open ending means the pain is still live.
7. How many times did it happen in the last month? Why: a count compares across interviews; “often” does not.

Instead of “How do you usually handle it?”, ask questions 1 and 7, because “usually” gets you the version of events the person wishes were true.

Pains and what they cost

1. What was the hardest part? Why: the person ranks the pain in their own words.
2. How many hours did it take that week? The answer gives you the cost in hours a week.
3. What did it cost in money: fees, penalties, overtime, lost sales? Why: the answer comes in dollars.
4. Who else had to spend time on it? Why: the answer comes in people, and each one is a cost.
5. What happens if it stays unfixed? Why: it separates a nuisance from a problem with a deadline.
6. What have you already tried? Why: no attempts at all often means the pain is too small to act on.
7. When did it last go wrong in a way that cost you? Why: the answer is a date plus a dollar figure.

Instead of “Is this a big problem for you?”, ask questions 9 and 10. A yes to the first costs the person nothing, and a number costs them a moment of honesty.

What they use now and what they tried

Before this stage, find your direct competitors so you recognize the names. The current alternative often sits in another category: a spreadsheet, a relative, the accountant who appears at tax time. Clayton Christensen of Harvard Business School framed this as customers “hiring” a product to do a job⁸.

1. What do you use for this today? Why: it names the real competitor, which is often a spreadsheet or a person.
2. How did you start using it? The answer shows the trigger and the channel that reached them.
3. What does it cost you a month? Why: the answer in dollars a month is your price anchor.
4. What extra steps do you take around it? Why: workarounds mark the gap a new product can fill.
5. What else did you look at before? Why: it gives the shortlist they compared.
6. When did you last switch, and what made you? Why: it names the event that moves this buyer.
7. What would you miss if you dropped it? Why: it shows what holds them in place, which your product has to match.

Instead of “What do you think of that tool?”, ask questions 18 and 20. An opinion of a competitor tells you nothing about whether the person would leave it.

How they decided to buy

1. Who uses it day to day? Why: the user feels the pain.
2. Who approved the money? Why: the buyer may be someone else, with other reasons.
3. Who could have said no? Why: the blocker is the person your pitch has to satisfy last.
4. What happened between deciding to look and paying? Why: each step is a place a sale can stall.
5. What almost stopped you? Why: it names the objection you will hear.
6. Where did you first hear of the option you chose? Why: it shows a channel that already works for this buyer.

In a business sale, the user, the buyer and the blocker can be three different people. Interview each role separately, because the owner, the manager and the outside accountant each describe a different problem.

Price and commitment

1. How do you pay for it: monthly, per use, yearly? Why: it shows the billing model the buyer already accepts.
2. Whose budget does it come from? Why: a named budget line means the spend is planned.
3. What did you pay the last time you bought something to fix this? Why: past spend is a fact; stated willingness to pay is a guess.
4. When did a price make you walk away from an option? Why: it gives an upper bound from a real decision.
5. Can we set up a short follow-up when there’s a first version? Why: a date on the calendar is a small commitment you can count.
6. Who else should I talk to about this? Why: an introduction costs the person some reputation, so it signals the problem matters to them.

Instead of “Would you pay this much for it?”, ask questions 30 and 31. People agree to hypothetical prices they would never pay.

Current and former customers

1. What were you doing right before you signed up? Why: it shows the trigger that brought them in.
2. What did you expect it to do in the first week? Why: the gap between expectation and the first week predicts churn.
3. What did you last use it for? Why: the last use is the job it does today.
4. What would you use if it were gone? Why: it names your real substitute.
5. What have you told others about it? Why: their words are the ones that sell it.
6. For former customers: when did you decide to stop, and what happened that day? Why: it dates the exit and names its cause.
7. For former customers: what do you use instead? Why: it shows who won them.

Instead of “How can we improve the product?”, ask questions 36 and 39. The first question hands the design work to the customer and returns a feature wish.

How the answers move the unit economics

In our example, the check’s unit economics look like this: a price of $550 a month^ex at 1 purchase a month^ex; a 40% margin^ex over a 10-month life^ex; a customer acquisition cost (CAC) of $900^ex.

Our formulas, as the check applies them, in the example:

• LTV = price × purchases per month × margin × lifetime in months = 550 × 1 × 0.4 × 10 = $2,200^ex.
• LTV:CAC = LTV ÷ CAC = 2,200 ÷ 900 = 2.44^ex.
• Payback in months = CAC ÷ (price × purchases per month × margin) = 900 ÷ (550 × 1 × 0.4) = 4.1^ex.

Each input maps to a question. Questions 17 and 30 test the price. Questions 34 and 39 test the lifetime, because they date when owners joined and left their last provider. Question 27 tests CAC, since a channel owners already use is cheaper to buy than a new one. Each extra month a client stays adds one month of margin to LTV. A lower price cuts both LTV and the monthly margin that pays back CAC. Put the numbers your interviews return into the unit economics calculator and compare them with the check’s estimate.