Product-Market Fit Score

How disappointed users would be without your product. The earliest reliable signal of PMF.

PMF Score = % of users answering "Very disappointed" if they could no longer use the product

What it measures

A survey-based leading indicator of product-market fit. Ask users: "How would you feel if you could no longer use [product]?" Options: Very disappointed, Somewhat disappointed, Not disappointed. The percentage answering "Very disappointed" predicts growth potential.

What to watch

Above 40%: Strong product-market fit indicator. Slack scored 51% when validating PMF. Companies crossing this threshold typically see organic growth accelerate.
Below 40%: Keep iterating. Your product solves a problem but isn't yet a must-have. Focus on understanding what "very disappointed" users love and double down on that.

In practice

A productivity tool launched with 28% PMF score. The team analyzed the "very disappointed" segment and found they all used one specific feature: automated time blocking. They rebuilt the entire product around that feature, and PMF score rose to 47%. The pivot was informed by users who already loved them, not average users.