The Mom Test is a short book that explains how to talk to customers during your idea validation stage.
I just love this little excerpt:
"I would definitely pay for something like that" is a useless statement.
According to the book, "I would" is a toxic phrase when it comes to conversation with a customer. Instead of talking about unclear future, we should get them to talk about the concrete past:
In this case, the past actions of customer reveal he never did anything to fix the problem. It's not even a real problem for him.
Don't believe "I would"s. Instead, look for "I did"s and "I did not"s.