What it is
Product-market fit is the stage where your product satisfies a real market need so well that customers stick, refer others, and demand pulls you forward. The term was popularized by Marc Andreessen.
Facts
- A well-known signal: 40%+ of users saying they'd be 'very disappointed' without your product (Sean Ellis test).
- Other signals: strong retention curves that flatten, organic word-of-mouth, and usage growing faster than you push.
- Before PMF, focus is on finding fit; after PMF, focus shifts to scaling it.
- PMF is usually felt as demand outpacing your ability to serve it.
Who it's for
Early-stage founders searching for traction before pouring money into growth.
How it helps you
Knowing whether you have PMF tells you when to stop iterating and start scaling, spending on growth before PMF wastes capital.
Caveats
PMF isn't a permanent checkbox, it can be lost as markets shift. Vanity metrics (signups, downloads) can mask weak retention, the real test.
Conclusion
Product-market fit is the milestone that changes everything, don't scale spending until retention and demand prove you've truly found it.