Strategy & Portfolio
PMF
Product-Market Fit — the degree to which a product satisfies strong market demand. When you have it, growth feels pull-based; when you don't, every customer feels like a push.
PMF (Product-Market Fit) describes the state in which a company's product strongly satisfies the needs of a specific market segment. The term was popularized by Marc Andreessen in a 2007 essay where he called PMF 'the only thing that matters' for a startup.
PMF is often described qualitatively: users love the product, word-of-mouth grows organically, the team struggles to keep up with demand, and customers are deeply upset at the thought of losing access. When PMF is absent, growth requires expensive pushing; when it's present, growth feels like pulling.
Quantitative signals of PMF: - Sean Ellis Test: >40% of users would be 'very disappointed' if the product disappeared - Retention curves that flatten (users stick around long-term) - NPS scores consistently above 50 - Organic/referral-driven acquisition growing without marketing spend - Short sales cycles and low churn rates
PMF is not binary — it exists on a spectrum and varies by market segment. A product might have strong PMF with one customer persona and weak PMF with another.
In Practice
Slack had clear PMF signals early: teams that adopted it refused to go back to email, usage metrics showed 93% retention after 90 days, and the company was growing 1,000%+ per year with almost no sales team. Contrast with a startup where the CEO manually onboards every customer, churn is 15%/month, and users say 'nice to have' rather than 'can't live without it' — those are signs of absent PMF.
Why It Matters
PMF is the fundamental milestone that separates startups that can scale from ones that shouldn't. Without PMF, hiring salespeople, spending on marketing, or raising a large round is burning money on a broken foundation. Most startup failures can be traced back to trying to scale before finding PMF. VCs pattern-match intensely for PMF signals before writing Series A checks.
VC Beast Take
The hardest truth about PMF: you usually know when you don't have it, even when you tell yourself you do. The tells are everywhere — low retention, high churn, customers who say they love it but don't actually use it, sales cycles that stretch on and on. The best founders have the discipline to stay in PMF-seeking mode — iterating, pivoting, talking to users — rather than scaling prematurely. The second-hardest truth: PMF in one market doesn't mean PMF in the next.