Substack

Substack, founded in 2017, is a newsletter publishing platform that allows writers to build and monetize subscriber communities. The company has raised more than $200 million in funding, including a $100 million Series C that gave it a $1.1 billion valuation. Backed by a16z, Substack provides tools for paid subscriptions, content publishing, and audience growth. Headquartered in San Francisco, the platform continues to expand its creator ecosystem and support independent writers building sustainable revenue.