The Mom Test
A short, practical book on how to talk to potential customers so you learn whether your idea is any good, instead of collecting polite compliments. It is the most recommended single book on customer conversations, and you can read it in an evening.
Book
Career Growth
Rob Fitzpatrick
About 130 pages, one or two evenings
Beginner
Paid (paperback, ebook, audiobook)
What it teaches
The Mom Test is about one problem: when you describe your idea to people, they are nice to you. Friends, family and even strangers will say it sounds great, and you will build something nobody pays for. Rob Fitzpatrick's answer is a set of rules for conversations that even your mother could not lie to you in. You talk about the other person's life and their past behaviour, not your idea. You ask about specifics ("when did this last happen, what did you do, what did it cost you") rather than opinions or hypotheticals ("would you use", "would you pay").
Why it matters for an indie product
Most small products fail because nobody wanted them badly enough, not because the code was bad. This book gives you a way to find that out in a week of conversations instead of six months of building. It also covers how to find people to talk to, how to keep conversations casual, how to spot compliments and fluff, and what counts as real commitment: time, reputation or money.
Time and prerequisites
The book is about 130 pages and reads in one or two evenings. No business background is needed. It is most useful when you have a problem area in mind and a list of people you could talk to next week.
Free versus paid
The book is paid, sold as a paperback, ebook and audiobook through the official site. The free alternative is Y Combinator's talk "How to talk to users" and the Startup School lessons on customer interviews, which cover the same core idea in less depth. If you can afford the book, it is worth it for the worked examples of good and bad questions.
What you can do after reading
- Write a list of questions about someone's past behaviour instead of your idea.
- Run ten short conversations and tell real demand from politeness.
- Ask for a concrete next step, such as a pre-order or an introduction, and treat a refusal as information.
Common questions
Is it only for startups? No. It applies equally to a template, a plugin or a mobile app: anyone selling to someone else.
Is it dated? The principles do not age. The examples are simple on purpose.
Source: momtestbook.com, checked 2026-09.
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