How to interview customers to validate your idea?

Why you should never ask customers, what their problem is, and other important aspects of the process.

Ana Bibikova
7 min readOct 14, 2021


When a VC asks you: “Did you talk to someone before building your product?” they refer to customer interviews. And almost every founder would give a positive answer to this question.

Photo by Christina @ on Unsplash

However, 8 out of 10 founders I mentor presume that “talk to someone” means they show the prototype of their product to their friend, get feedback that sounds like “Wow! Wonderful idea!” — and that’s the validation of their concept. Here’s a big surprise: this is not a validation and the prototype demo is NOT a customer interview.

These are my favourite quotes from Rob Fitzpatrick’s The Mom Test, a book that every startup founder should know by heart:

The conversations where you talk about our product only give us rope to hang ourselves

Whenever I hear a customer compliments me I hear alarms going ”you’ve messed it up”

People know what their problems are but they don’t necessarily know how to solve them.

If you go to Google and start researching the subject of customer interviews you’ll stumble upon fancy techniques like “Jobs-to-be-done framework”, “4 lists formula”, “Stages of awareness differentiation” etc.

My advice is: when you’re on ideation stage — forget all these fancy words. Just go and interview people that you consider to be your potential customers.

But follow those simple rules:

  1. NEVER ask a person what they think about your idea or product.
  2. NEVER ask them if they would pay someone for solving their problem. Instead, ask them to describe their existing process of solving the problem you think they have. Ask them to walk you through their thinking process and the way they look for a solution.
  3. If you’re building a solution to the problem based on the tools that already exist and that you presume customers are unhappy about — ask, what exactly are they unhappy about. What “work around” have they found to deal with inconveniences they see in the existing tools.
  4. NEVER ask a customer…