Product & Analytics / Product Strategy
Product-Market Fit Score ~ (also "Sean Ellis test", "very-disappointed score", "PMF score")
A survey-based read on product-market fit -- the share of users who would be "very disappointed" if they could no longer use the product.
The fork, why two teams get different numbers
The metric centers on one question ("How would you feel if you could no longer use [product]?" -- Very disappointed / Somewhat disappointed / Not disappointed) and a widely-cited 40% "VERY DISAPPOINTED" benchmark as the fit line.
In the Metric Library
- The full fork, both definitions worked all the way through
- The trap that makes the number lie, on a real export
- Every formula variant, spelled out
- The reconciliation anchor, what to tie it to and when to refuse
Reference: Sean Ellis product-market-fit survey framework cited as reference (the "very disappointed" question and ~40% heuristic) · not reproduced; survey-methodology conventions