Tips for Successful Customer Interviews (The McKinsey way)

A startup journey starts with a vision of a new product, how that product will reach its customers, and why people should buy it.

But what startup’s founders initially believe about the market and potential customers are just educated guesses.

So the primary goal of Customer Validation is turning the founders’ initial hypotheses about their product, market, and customers into facts.

There are no facts inside your building, so get outside.
— Steve Blank, the author of the “Lean startup method”

But how to do it the right way?

Interviewing is a primary data collection method at McKinsey (one of the world’s top consulting firms.)

Let’s review some interviewing tips from McKinsey and identify how you can successfully implement their interview techniques in your organization.

I’ve summarized the key points below:

  • Create a nice ‘Cover letter’ where you introduce yourself and describe the project briefly. Cover letter is sent along with the interview guide (Described below.)

  • Develop an interview guide. 

  • Send your interview guide to the interviewee at least two days in advance.

  • Always write a ‘Thank you’ note with a follow-up and send it after the interview.

Interview Discipline


When it comes to the actual interview, the pre-interview communication matters. It sets the tone for the rest of your time with the interviewee.



Humans are prone to what’s called cognitive bias, which makes them unconsciously irrational.

There are 150 different types of biases, including the so-called framing effect.

This concept states that, when faced with the same options, people will make different choices depending on how the alternatives are framed.

So, information is key, and to get it you need to establish an amicable rapport with your interviewee.

That’s why one goal of interviewing is to get the other party to talk a lot. As she does, you’ll be able to figure out what she feels and wants.

That being said, nobody is going to provide you with information if they don’t trust you, and that’s why rapport is essential.

If you manage to establish it, you’ll build trust in the process, making it much more likely that the other person will divulge useful information.

But how can you establish rapport?

Closely listening to and even repeating what your counterpart says can build trust.

So, you know that trust is key, but how do you establish it?

The best route is to engage in active listening, which means showing empathy and demonstrating that you understand what the other person is going through.

Several techniques can help.

The first is called mirroring, which means repeating what your interviewee says but with an inquisitive tone. 

But why does mirroring work?

Largely because it makes the other person feel that you’re similar to him. After all, your counterpart is only human and will naturally be drawn to similarities.

That’s because, just like other animals, people like to be in groups with similar traits.

Doing so gives us a sense of belonging and forges trust.

This is powerful in a communication: when your counterpart starts to trust you, he will become more likely to talk and find a solution.

To test the effects of this approach more scientifically, the psychologist, Richard Wiseman conducted an experiment in which waiters would take orders from customers.

One group of waiters was asked to use mirroring while the other was asked to utilize positive reinforcement through phrases like “no problem” and “great.”

In the end, the waiters who mirrored the orders made by customers received much higher tips, earning 70 per cent more than the other group.

The post-interview

The post-interview follow-up also adds value to the interview process. It gives you a chance to confirm what you heard and to ensure you understood what was said. It is much better to have that clarification earlier in the process, as the error can magnify over time. (Remember those school-yard games of "telephone" in which a sentence gets whispered around a circle and emerges hilariously unrecognizable?)

Be Prepared 

Write an Interview Guide

An interview guide is simply a written list of the questions you want to ask, arranged in the order you expect to ask them. It should be brief. There are two reasons why you should have such a guide. 

First, placing your thoughts on paper forces you to organize them.

Second, the guide helps the interviewee to identify the topics you intend to cover in the interview and prepare accordingly.

The successful interview guide entails:

  • The list of the key objectives you would like to obtain. You should end up with 2 or 3 primary objectives for the meeting.

  • A logical structure around the key objectives. 

  • Keep it dry. Your focus should be on getting answers to the key questions in a limited time. Anything more is gravy. 

A Few Tips

1. Have the interviewee’s boss set up the meeting (If applicable.)

2. Listen, don’t lead.

3. Don’t ask for too much.

4. Adopt the Columbo tactic.

Lieutenant Columbo was a 1970s TV cop played by Peter Falk. He would often finish questioning a suspect and then pause by the door to ask one more question—usually a zinger. This tactic succeeded because the suspects often dropped their guard and allowed the truth to come out. You can try this approach if you think an interviewee is holding out on you. Who knows, you just might crack the case.

P.S. And don’t forget to close with every McKinsey-ite’s favorite question: "Is there anything I forgot to ask?" Every now and then, it hits pay dirt.

A Thank-You Note

Writing thank-you notes is not just good etiquette; this is good business.

Imagine the nice feeling you get when you receive an unexpected thank-you letter. Many of us need to fight the temptation to neglect this courtesy because we keep moving forward at such a rapid pace. Take time to smell the roses, and thank someone for them as well.

Consultants, especially consultants at McKinsey, treat interviews with the utmost respect. They spend a lot of time and effort preparing for them and learning from them. You should, too.

Be Sensitive

Some people see interviewees as a source of information to be drained dry. For a better outcome, use a different approach. Try to establish a connection with the interviewee. Treat the interview as a chance to meet a new person and actively involve her in the problem-solving effort. 

To crack the ice, you can begin with a big picture of what you are trying to accomplish and why you are meeting with that particular person. 

The interview is a two-way exchange. If you let the interviewee become your partner in the process, you will be able develop a great relationship.


To increase the effectiveness of data gathering through your interviews, follow these principles to make the most out of interviewing:

  • Structure your interviews. Create an interview guide.

  • Document what you learn. Create a MS Word/Google Doc/DropBox paper temple to summarize findings. Use it for the each interview.

  • Interviewing is about listening.

  • Be sensitive.

  • Close with a question: "Is there anything I forgot to ask?"

  • Write a good old-fashioned handwritten or typed thank-you letter. 


To help you increase the effectiveness of data gathering through your interviews download this Google Doc template and use it in your organization to better structure interview sessions.

If you have any questions about this topic or need help, leave a comment below with your question and I’ll answer it.

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Thank you for reading!

Alex Gilev

I strategize and design innovative software for SaaS companies that want big results.