📖 Book
✓ Link checked
Paid
Beginner
Why we picked it
The single best thing ever written on customer conversations. It teaches you to ask about the customer's life and past behaviour, not your idea, so you can't be lied to. If a founder reads one thing before talking to a single customer, it's this.
From
momtestbook.com
by Rob Fitzpatrick
~130 pages
- Talk about their life, not your idea.
- Ask about specifics in the past, not opinions about the future.
- 'That's so cool, I'd totally buy it' is a compliment, not data, dig for commitment and evidence.
Open
momtestbook.com →
📄 Article
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Free
Beginner
Why we picked it
The canonical fake-door test, told by the founder who ran it. Buffer started as a two-page site: one page pitched the tool, a pricing button led to an email capture, and every signup got a personal note. Real demand, real conversations, a paying customer in weeks, and not a line of product code.
From
Buffer
by Joel Gascoigne
~10 min read
- Test willingness to pay with a pricing page before you build.
- Email every signup by hand and start a conversation.
- A landing page measures behaviour, not opinions.
Open
buffer.com →
📄 Article
✓ Link checked
Free
Beginner
Why we picked it
The two ways to fake a product while you test real demand. Do the work by hand in the open (concierge), or hide the manual work behind a front so users think it is automated (Wizard of Oz, the way Zappos started). Clear examples of when each one fits.
From
LogRocket
~12 min read
- Concierge is transparent, Wizard of Oz is hidden.
- Both let you sell before you build.
- Match the method to what you are unsure about.
Open
blog.logrocket.com →
📄 Article
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Free
Beginner
Why we picked it
The idea that started the lean movement, from the person who coined it. No business plan survives first contact with customers, so stop defending assumptions at your desk and go test them on real people. Short, blunt, and foundational.
From
steveblank.com
by Steve Blank
~8 min read
- Your idea is a set of guesses until customers test it.
- Facts live outside the building, not in your plan.
- Expect to be wrong, and plan to learn from it.
Open
steveblank.com →
📄 Article
✓ Link checked
Freemium
Beginner
Why we picked it
Todd Jackson studied how dozens of now-large companies validated their very first idea. The pattern that repeats: deliver the outcome by hand, talk to real users, and watch for genuine emotion. A polite 'that's cool' is a no. Strong reactions are the signal you want.
From
Lenny's Newsletter
by Todd Jackson
~15 min read
- Manual delivery beats a survey for early signal.
- Look for strong emotion, not politeness.
- Great ideas usually start from a problem you have lived.
Open
lennysnewsletter.com →
📄 Article
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Free
Intermediate
Why we picked it
Turns the vague feeling of product-market fit into a number you can move. Ask users how they would feel if they could no longer use the product, then track the share who say 'very disappointed'. Under 40 percent means keep working. A test you can run on an idea long before you scale it.
From
First Round Review
by Rahul Vohra
~20 min read
- The 40 percent 'very disappointed' benchmark for product-market fit.
- Segment to your high-expectation customers and build for them.
- Make the fit score a metric you improve quarter by quarter.
Open
review.firstround.com →
📄 Article
✓ Link checked
Freemium
Intermediate
Why we picked it
If you are selling to companies rather than consumers, this is the specific playbook. Four concrete ways founders got signal before building, from doing the job by hand for one customer to interviewing dozens of potential users first.
From
Lenny's Newsletter
by Lenny Rachitsky
~12 min read
- Do the job by hand for one real customer before automating.
- Interview a wide set of potential users before committing.
- B2B signal looks different from consumer signal.
Open
lennysnewsletter.com →
✍️ Essay
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Free
Beginner
Why we picked it
The definitive essay on where good ideas come from: notice problems you personally have, don't force it. Use it as the lens for judging whether your idea is a real problem or a solution in search of one.
From
paulgraham.com
by Paul Graham
~20 min read
- Live in the future and build what's missing.
- The best ideas look like bad ideas at first (schleps and hard-to-explain).
- Start with problems you have, in a domain you actually know.
Open
paulgraham.com →
Why we picked it
The permission slip to recruit users by hand, do things manually, and deliver 'insanely great' experiences to your first few customers. The cheapest, most honest way to validate demand is to go get it one person at a time.
From
paulgraham.com
by Paul Graham
~15 min read
- Recruit your first users manually, don't wait for them to come.
- A tiny group of users who love you beats a big group who like you.
- Manual, unscalable effort early is a feature, not a failure.
Open
paulgraham.com →
Why we picked it
The most systematic step-by-step process for de-risking an idea, built around the Lean Canvas. Where The Lean Startup gives philosophy, Running Lean gives you the exact sequence of experiments to run this month.
From
LEANSTACK
by Ash Maurya
~240 pages
- Capture your business model on one Lean Canvas before building.
- Rank and attack your riskiest assumptions first.
- Run problem interviews, then solution interviews, then an MVP.
Open
leanstack.com →
Why we picked it
The book that gave the world 'MVP', 'build-measure-learn', and 'validated learning'. It reframes a startup as a series of experiments, not a bet, the mental model everything else in this category builds on.
From
theleanstartup.com
by Eric Ries
~330 pages
- Progress = validated learning, not features shipped.
- Build the minimum that produces a real learning loop.
- Decide pivot-or-persevere on evidence, on a schedule.
Open
theleanstartup.com →
Why we picked it
A short, practical field guide to customer discovery: who to talk to, how to find them, and how many. Pairs perfectly with The Mom Test, Fitzpatrick teaches the questions, Constable teaches the logistics.
From
talkingtohumans.com
by Giff Constable
~80 pages (free PDF available)
- Decide who you need to learn from before you start.
- Recruiting interviewees is a skill, scripts and channels included.
- Get out of the building; patterns emerge faster than you expect.
Open
talkingtohumans.com →
