The subscription platform where writers own their audience — unicorn at $1.1B
HQ: San Francisco, CA, United States | Founded: 2017 | Employees: ~150-200 (deliberately small for its scale) | Stage: Series C ($100M at $1.1B valuation, July 2025) | Website: https://substack.com
Substack is a publishing platform where writers, journalists, podcasters and video creators publish directly to their audiences and get paid through subscriptions. The deal is simple and radical: creators keep 90% of subscription revenue (Substack takes 10% plus payment fees), and — uniquely — the email list itself belongs to the creator and can be exported at any time. Publishing tools are free; Substack only earns when writers do.
The company was founded in 2017 in San Francisco by Hamish McKenzie, a New Zealand-born journalist (ex-Pelandar, ex-Tesla blogger); Chris Best, co-founder and CTO of messaging app Kik, who became Substack's CEO; and Jairaj Sethi, also ex-Kik, its head of engineering. The original thesis: the ad-supported internet had broken the business model of writing, and the fix was to let readers pay writers directly — an email newsletter, a payment button, ownership of the audience.
Growth was steady until the media-industry crackup made it explosive. High-profile writers and outlets moved over; Substack Pro (advances to big names) courted controversy and was retired; and after 2022 the platform leaned into expansion: a consumer app, Notes (a Twitter-style shortform feed), a recommendations network that turns Substack's writers into a growth engine for each other, podcast hosting, video, and live video. By mid-2025 the company reported 5M+ paid subscriptions and 50M+ active subscriptions, with the app driving a large share of new subscriptions.
In July 2025 Substack raised a $100M Series C led by Bond and The Chernin Group at a $1.1B valuation — its first round since 2021 ($65M Series B at ~$650-700M). The company remains deliberately small (~150-200 people) for its cultural footprint, and has courted both adulation (creator empowerment) and criticism (moderation choices, its laissez-faire stance on controversial writers).
Substack made a bet no media company dared: writers should own the relationship with their readers — including the email list, which stays portable if they leave — and the platform should live on a 10% cut of whatever writers earn. For years that looked like a nice little business. Then the media landscape did Substack's marketing for it: mass layoffs, collapsing trust, and Twitter's chaos sent every serious journalist and commentator looking for a direct line to their audience.
By its July 2025 Series C — $100M led by Bond and The Chernin Group at a $1.1B valuation — Substack had crossed 5 million paid subscriptions (up from 1M in 2021 and 3M in early 2024) and 50M+ active subscriptions, with writers on the platform collectively earning well over $450M a year. The strategic pivot that powered the round: Substack stopped being just a newsletter tool. It shipped an app, a Notes-style shortform feed, recommendations that let writers grow off other writers' audiences, podcast and video hosting, and live video — deliberately re-creating the parts of Twitter writers missed, minus the algorithmic whimsy.
The model's elegance is its fragility. 90/10 revenue splits mean Substack's take (~$50M estimated on ~$500M writer earnings) is thin relative to its $1.1B valuation — a 22x revenue multiple critics love to point out. Its answer is volume and expansion: more media types, more social discovery, ads-free but subscription-maximal. The risks are equally clear: platform dependence cuts both ways (creators leave for Beehiiv/Ghost when fees matter), the app/social push has alienated some purists, and moderation fights over big-name writers are a recurring brand tax. But the core flywheel — writers earn, Substack grows — is one of the cleanest alignments in the creator economy, and it just became a unicorn on it.
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