Startup Growth · March 9, 2026 · 8 min read
How to know if you actually have product-market fit (5 real signals and 3 that are lying to you)
Product-market fit is what happens when we leave the room. Five signals survive our absence. Retention that holds without heroics, referrals nobody asked for, users who rebuild their work around the product, demand that arrives on its own, and the 40% who'd be very disappointed to lose it. Sign-ups, a strong NPS, and deals we personally closed all get measured while we're standing there, which is exactly why they flatter.