"Hey mum, I have this great idea for an app! It does xyz. What do you think?"
"Great idea honey! Have you eaten some fruit today?"

Building an app after this kind conversation is a bad idea. That's the premise of The Mom Test, a book that gives really good guidance on customer interviews.

It's an extreme example, but it's one that reflects many conversations we have with people we seek confirmation from - even potential customers.

Questions like these:

• "Do you think this is a good idea?"
• "Is this something you'd be interested in purchasing?"
• "Would you like to know when we launch?"

As I put into practise some of the principles of The Foundation with Dane Maxwell, I find myself doing customer interviews in ways I never did them before.

On one recent one, I was asking questions of an operations executive, trying to tease out how to improve that company's physical site management tools for the company's growing site footprint. I kept asking different questions, but the questions seem to be going nowhere. The exec seemed disinterested, and was answering in a formulaic manner. "I guess I'd like them to be more efficient." That kind of thing.

I tried something I had learned recently: a question that might kill my entire idea of a product to improve physical site operations.

"What would happen if we just shut down all the sites tomorrow?"

The exec didn't bat an eyelid.

"Nothing. We'd go on, and probably focus more on online, which is more scalable."

BAM. The exec didn't even WANT physical sites. They were a pain in the ass! The exec - in fact, the whole company - would far prefer if everything were online.

This question saved me probably hours of more questions. And the methodology may have saved me months (years?) and an untold amount of money and energy building a product to improve something that people may not even believe should exist.