🧲 Product-Market Fit
Product-Market Fit (PMF) is the state where your product satisfies a strong market demand. Marc Andreessen described it as "being in a good market with a product that can satisfy that market." Before PMF, nothing else matters — growth hacking, optimization, and scaling are all premature. After PMF, everything gets easier. The challenge is that PMF is not binary — it is a gradient that requires continuous calibration.
PMF Signals
Retention
Users keep coming back without prompting — the strongest PMF signal
Organic Growth
Users tell others about the product without incentives
Sean Ellis Test
40%+ users say they would be "very disappointed" without the product
Revenue Growth
Increasing willingness to pay and expanding deal sizes
Real-World Example
Superhuman (email app) operationalized PMF measurement using the Sean Ellis test. They surveyed users, segmented responses, identified the "somewhat disappointed" group, analyzed what would make them "very disappointed," and built features targeting that conversion. This systematic approach increased their PMF score from 22% to 58%.