Definition
Product-market fit (PMF) is the state in which a product genuinely satisfies a real, sizable market need, so that demand pulls the product forward. The concept was popularized by investor Marc Andreessen.
Meaning and usage
There is no single formula for judging PMF; common signals include a retention curve that flattens rather than keeps declining, users who recommend the product unprompted, and organic growth that does not depend on paid acquisition. In Andreessen’s phrasing, before PMF almost nothing works, and after PMF it is hard to get things wrong.
Usage
Early-stage startup discussions treat PMF as a milestone: prove that the market wants the product before scaling, hiring or raising big rounds. Investors also frame their diligence around whether PMF exists.
Related and confusable terms
PMF is a qualitative judgment about whether the product is needed, and metrics such as ARR are often cited as evidence. Reaching PMF does not guarantee a VC investment, nor does it mean the venture is profitable — that is what ROI is for.