Formula
Users using the feature / Users eligible for the feature x 100
How to measure
Define eligibility, like having access to the feature, then track what share of eligible users engage with it at least once and again in a following period.
Why track it
Feature adoption tells a product team whether new investment is actually changing behavior, not just shipping into a void.
Example
A new automation feature reaches only 8% adoption among eligible users, prompting a redesign of its onboarding prompt.