Product-Market Fit
The state where a product satisfies strong market demand — typically signaled by usage growing without forced acquisition and customers being upset if the product disappeared.
Product-Market Fit (often shortened to PMF) is the moment a startup transitions from "trying to find a market" to "trying to serve a market that has found it." Marc Andreessen popularized the phrase in his 2007 essay The Only Thing That Matters, where he argued PMF is the single binary that determines startup outcomes — every other variable (team, idea, execution) matters far less.
How you know you have it
Operational signals:
- Organic growth (users tell others)
- Retention curves that flatten rather than decay to zero
- The team is overwhelmed by demand rather than chasing it
- The Sean Ellis test: >40% of users say they'd be "very disappointed" if the product disappeared
How you know you don't
The inverse — usage requires constant marketing push, retention curves trend to zero, growth requires increasingly expensive customer acquisition, the team spends more time selling than serving.
Why it matters
PMF is a phase transition, not a gradual improvement. Pre-PMF, most strategic frameworks (SWOT, Five Forces, OKRs) are premature — you don't know what business you're in yet. Post-PMF, the same frameworks become useful for scaling decisions.
The mistake most startups make is treating PMF as a destination they can reach by working harder. Sometimes the right answer is to pivot the product or the market until the fit shows up — Andreessen's argument was that finding PMF is the founder's job, not forcing it.
Related
- JTBD — useful framework for getting toward PMF by clarifying what job customers are hiring you to do
- North Star Metric — once you have PMF, the single metric that captures the value you're delivering
- Retention cohort