Growth Metrics

Product-Market Fit (PMF)

The degree to which a product satisfies strong market demand — evidenced by organic growth, high retention, and unprompted customer enthusiasm.

Product-market fit is the elusive state where a product meets a genuine, recurring need so well that customers would be genuinely disappointed without it. The most widely cited test is the 40% rule: if at least 40% of surveyed users say they would be very disappointed if they could no longer use the product, you likely have PMF. Behavioural signals of PMF include organic referrals without prompting, retention curves that flatten rather than declining to zero, and customers who push back hard when you propose removing features. Before PMF, the priority is learning — running experiments and talking to customers. After PMF, the priority shifts to scaling distribution and operations to meet demand. Achieving PMF does not mean the work is done; the fit must be maintained as the market, competition, and product evolve.