Metrics & frameworks

Product-Market Fit

Definition

Product-market fit is the state where a product satisfies a strong market demand — customers buy without heroic selling, retain without heroic support, and refer others unprompted.

Why it matters in B2B GTM

Marc Andreessen's original framing still holds: you don't have product-market fit if you have to ask whether you have product-market fit. When it lands, the signals are unambiguous — usage spikes, retention holds, sales cycles compress, and word of mouth does work your marketing team can't.

The most-cited proxy metric is Sean Ellis's question: "How would you feel if you could no longer use this product?" If 40%+ of active users say "very disappointed," you're likely there. Below 25%, you almost certainly aren't.

Product-market fit is segment-specific, not product-specific. You can have fit with one ICP and not another. The right move after early fit is usually to double down on the segment that's working, not to chase the next segment until the first is repeatable.

How ICPGTM uses it

ICPGTM Playbooks helps founders find fit faster by stress-testing three ranked ICPs before they commit — so the wedge you double down on is the one most likely to produce "very disappointed" responses, not just polite enthusiasm.

Related terms

Apply this to your own product

Generate three ranked ICPs, a buyer committee, outreach drafts, and a 30/60/90 GTM plan in about 90 seconds — your first playbook is free.