Measuring Product-Market Fit

Scope

Covers

• Measuring PMF using a triangulated signal set (survey + behavior + customer evidence)
• Running and interpreting the Sean Ellis “Very Disappointed” survey (overall + by segment)
• Reading retention curves / cohort retention as PMF evidence (and knowing when they mislead)
• Using reference-customer / advocacy signals as an additional PMF proxy
• Detecting PMF drift (market shifts, rising expectations, competitive resets) and setting a re-measurement cadence
• Special handling for marketplaces (measure PMF per side; focus on the “hard side” first)

When to use

• “Do we have PMF? For which segment?”
• “Run a Sean Ellis PMF survey and tell me what it means.”
• “Build a PMF scorecard with retention + survey + references.”
• “Our market shifted—did we lose PMF?”
• “We want a go/no-go signal for scaling growth spend or launching publicly.”