📖 Book
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Paid
Beginner
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 →
✍️ Essay
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Free
Beginner
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 →
1 founder recommend
📄 Article
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Freemium
Intermediate
Market size is meaningless until you know exactly who you're for, and Lenny turns that into a concrete, repeatable ICP exercise from real B2B operators. It grounds your SAM in an actual customer definition instead of a fuzzy segment.
From
Lenny's Newsletter
by Lenny Rachitsky
~15 min read
- Define the specific customer you serve before you size the market, not after.
- A sharp ICP makes your bottom-up market math credible and your GTM focused.
- Narrowing 'who it's for' is what makes a small beachhead winnable.
Open
lennysnewsletter.com →
✍️ Essay
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Free
Intermediate
Cohen answers the fear founders have about niching down, that naming one very specific, concrete customer actually attracts more business, not less. That reassurance matters before you commit to the acute pain slice your short answer describes instead of the whole SMB bucket, since narrowing your message sharpens it for the exact person deciding, without losing adjacent customers who share their problem.
From
A Smart Bear
by Jason Cohen
15 min read
- A vivid, specific ideal customer sharpens your product and message more than a broad segment does
- People who are not exactly your ideal customer but share their problem will still buy
- Fear of excluding people by being specific is usually unfounded in practice
Open
longform.asmartbear.com →
✍️ Essay
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Free
Intermediate
This piece attacks the exact mistake domain experts make: describing a market by job title or industry instead of by the situation that creates urgent pain. It gives you language to replace 'anyone in my industry' with the specific circumstance that actually predicts who will buy.
From
A Smart Bear
by Jason Cohen
- Demographics and job titles are weak predictors of who buys; situation and pain are strong predictors
- Interview customers to find the trigger event that made them go looking for a solution
- Two people with the same job title can be completely different customers
Open
longform.asmartbear.com →
📖 Book
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Freemium
Beginner
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 →
📄 Article
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Free
Intermediate
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 →
📖 Book
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Paid
Intermediate
The best book on positioning against competitors by understanding the alternatives customers actually consider. Directly turns competitive research into a market advantage.
From
aprildunford.com
by April Dunford
~200 pages
- Your real competition is often the status quo, not another product
- Start positioning from the competitive alternatives your buyers consider
- Differentiated value comes from your unique capabilities vs those alternatives
- Choose the market frame that makes your strengths obvious
Open
aprildunford.com →
📖 Book
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Paid
Intermediate
Moore's beachhead idea is the definitive case for winning one narrow segment before you touch the broader market, which is precisely how you compete when big players already own the mainstream. He argues you pick a target segment big enough to matter but small enough to lead, then dominate it before expanding. In a crowded market that focus is not timidity, it is the only way a small team gets a foothold.
From
Geoffrey A. Moore
by Geoffrey A. Moore
~240 pages
- Win a single beachhead segment completely before spreading resources across a broad market
- Choose a niche big enough to matter but small enough to lead, and concentrate everything there
- Mainstream, pragmatic buyers need a compelling, proven reason to switch, which a narrow focus lets you deliver credibly
Open
geoffreyamoore.com →
✍️ Essay
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Free
Intermediate
This is the classic mental model for exactly your question: how customer count trades off against deal size. Janz maps five viable paths to $100M in revenue, from 1,000 enterprise customers paying $100k+ each (elephants) down to 10 million ad-monetized users (flies), so you can see where a low-count, high-value market sits and what it demands of you. Treat it as a lens for pressure-testing your own model, not a promise that any single path is right for you.
From
The Angel VC
by Christoph Janz
~12 min read
- There are several ways to reach $100M in revenue, and fewer, higher-value customers (elephants and deer) is a legitimate one, not a compromise.
- Each path demands very different skills: elephant hunting needs real enterprise sales muscle, while the mouse and fly paths need virality and marketing.
- The right question is not just how big your market is, but whether your acquisition channels are scalable and profitable for the segment you are chasing.
Open
christophjanz.blogspot.com →
✍️ Essay
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Free
Advanced
Coelen explains why founders can't segment their market from a desk using industry reports, they have to talk to real customers to find the fault lines, which directly supports the short answer's call to interview people outside your own bubble. It is a clear, modern explainer written specifically for founders stuck exactly where this question starts.
From
Doctor Market Fit
by Jeroen Coelen
- You cannot find your real segment from market research reports alone, only from customer conversations
- Keep your beachhead small enough that you can execute against it with total focus
- Broad segmentation is usually a sign you haven't done the qualitative work yet
Open
doctormarket.fit →
✍️ Essay
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Free
Advanced
This piece gives you a checklist for evaluating whether a slice of your industry is a genuine beachhead: urgent problem, willingness to try something new, and reachability, which maps closely to the acute pain, budget, and fast decisions test in the short answer. Use it to pressure test your first cut of the market before committing resources to it.
From
Doctor Market Fit
by Jeroen Coelen
- A strong beachhead segment has an urgent, top of mind problem, not a nice to have
- The segment must be open to trying an unproven, novel solution, not just aware of the pain
- Reachability matters: you need a real way to find and talk to this segment cheaply
Open
doctormarket.fit →
✍️ Essay
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Free
Beginner
This is a practical, tactical follow up to the ICP essays above: once you have named your narrow slice, here is how you actually find and reach the first handful of people in it. It closes the loop between defining an ICP on paper and doing the legwork to meet real members of that segment.
From
A Smart Bear
by Jason Cohen
- Go directly to where your narrow segment already gathers, online or offline
- A precise ICP makes cold outreach far more effective because the message can be specific
- Early customers found this way become your best source for referrals into the same segment
Open
blog.asmartbear.com →
This is the practical step after you accept that not everyone in your industry is your customer. It walks through turning a vague 'everyone in my field' into a sharp, testable ideal customer profile, with concrete before and after examples (from 'small businesses' to 'boutique marketing agencies with under 10 employees'). For a domain expert convinced the whole market needs their product, it is a clear push to pick the narrow segment that needs it most and start there.
From
Startups.com
by Ryan Rutan
About 12 minute read
- Trying to serve everyone means you resonate with no one. Specificity in who you target sharpens positioning, messaging, and conversion.
- A good ICP is concrete: firm size, role, situation, and pain, not a broad industry label.
- Nail the ICP first. Marketing, sales, and product all get easier once you know exactly who you are building for.
Open
startups.com →
This explains the exact cognitive trap behind insider bias: once you know a domain deeply you cannot un-see it, so you assume others feel and understand what you do. Naming the bias helps you catch yourself pitching to people who do not share your context. Short and practical.
From
CXL
by CXL
~12 min read
- Expertise makes you assume others share your knowledge
- The bias hides which pains outsiders actually feel
- Test your language and value on people outside your field
Open
cxl.com →
