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PMF Story · Media · Subscriptions

How Substack Found Product-Market Fit

7 min · 6 sources · Updated Jul 2026

Substack didn’t launch a mass-market product and hope writers showed up. It hand-recruited a handful of respected independents, proved they could out-earn a salary on subscriptions alone, and let their audiences pull the next writers in.

PMF snapshot
FoundersChris Best, Hamish McKenzie, Jairaj Sethi
Initial customerIndependent writers with a devoted, addressable audience
The wedgeA few marquee newsletters with paying subscribers from day one
Business modelFree to publish; Substack takes ~10% of subscription revenue
Growth engineWriters bring their own readers — a self-reinforcing loop
The turning pointOne writer proving six figures was possible without ads
Where it landed~$650M valuation, Series B

The early problem

The founders — a Kik co-founder and two journalists — watched ad-driven media reward sensationalism over substance, while independent writers had no simple way to charge readers directly. The question was blunt: could high-quality writing be funded by the people who valued it, instead of by advertisers optimizing for clicks?1

Two bets to test at once

Substack’s model depended on two things being true simultaneously: that readers would pay for writing, and that credible writers would leave the safety of a masthead to go independent. Rather than test them separately, the team found writers who could validate both at once — people with an existing, trusting audience.2

Do things that don’t scale

Instead of a broad launch, the founders worked hand-in-hand with a small set of prominent writers — setting up their publications, coaxing them off free platforms, and treating each one as a partner rather than a user. Bill Bishop’s China newsletter, Sinocism, became the proof point: a serious paid audience, quickly, with no advertising.2,3

The key move

They didn’t build for “writers” in the abstract. They personally recruited a few respected independents, gave them white-glove support, and used one breakout paid newsletter to show every other writer what was possible — turning marquee creators into a growth loop that never needed paid acquisition.2

How it unfolded

2017Substack launches; Bill Bishop’s Sinocism becomes an early paid flagship.
2018Andreessen Horowitz backs the company; the writer roster widens.
2020A wave of journalists leaving newsrooms accelerates adoption.
2021Raises a Series B at roughly a $650M valuation.

What founders can copy

Recruit the supply side by hand
In a two-sided market, win a few high-signal suppliers personally before automating anything — their audiences become your distribution.
Find the user who tests two bets at once
A writer with an existing paying audience validated both “will readers pay?” and “will writers leave?” in a single move.
Make one success undeniable
A single writer earning real money on subscriptions did more to recruit the next hundred than any pitch could.
Align the model with the mission
Taking a cut of subscriptions — not selling ads — kept Substack’s incentives pointed at the writer’s success, which is exactly what writers were buying.
What was specific to Substack

Marquee writers with portable audiences were the unlock for a newsletter platform — a lever most products don’t have. The transferable idea is narrower: in a marketplace, hand-pick and over-serve the supply side that carries its own demand.

Sources

6 referenced
01Substack — founding thesis and “why we started Substack”
02a16z — investment memo and creator-economy commentary
03Sinocism / Bill Bishop — early paid-newsletter case study
04The New York Times — coverage of the writer exodus to newsletters
05Nieman Lab — reporting on subscription publishing economics
06Founder interviews with Chris Best and Hamish McKenzie

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