The Mom Test: How to Talk to Customers & Learn If Your Business Is a Good Idea When Everyone Is Lying to You

Steve Blank’s original book on Customer Development, 4 Steps to the E.piphany,

Every time you talk to someone, you should be asking at least one question which has the potential to destroy your currently imagined business.

The real failure is

Rule of thumb: In early stage sales, the real goal is learning. Revenue is a side-effect.