What is Product-Market Fit?
Product-market fit (PMF) is the degree to which a product satisfies strong market demand. Marc Andreessen defined it as 'being in a good market with a product that can satisfy that market.' It's the most important milestone for any startup or new product.
Signs of product-market fit include: organic growth without marketing, high retention rates, customers becoming evangelists, demand exceeding supply, and usage data showing deep engagement rather than surface-level adoption.
Signs you DON'T have product-market fit: high churn, users sign up but don't return, growth only comes from paid acquisition, users need extensive onboarding to see value, and feature requests are scattered across unrelated areas.
Richard Ewing's perspective: 'The best AI product I ever led had zero customers' — a reminder that technical excellence doesn't guarantee product-market fit. Validation must be economic, not just technical.
Why It Matters
Without product-market fit, nothing else matters. Marketing spend is wasted. Engineering effort is misdirected. Hiring is premature. PMF is the prerequisite for everything else.
Frequently Asked Questions
What is product-market fit?
Product-market fit means you've built something that a specific market wants badly enough to pay for, use repeatedly, and recommend to others.
How do you measure product-market fit?
Sean Ellis test: ask users 'How would you feel if you could no longer use this product?' If 40%+ say 'very disappointed,' you have PMF. Also look at retention curves, organic growth, and NPS.
Related Terms
Need Expert Help?
Richard Ewing is a Product Economist and AI Capital Auditor. He helps companies translate technical complexity into financial clarity.
Book Advisory Call →