What product telemetry data actually predicts feature stickiness, not just initial usage?

Been tracking feature adoption for months but users keep churning after trying things once.

Most metrics focus on first-time usage but that doesn’t tell me if people will actually stick with the feature long-term.

What data points have you found that actually correlate with sustained engagement rather than just curiosity clicks?

Day 7 retention beats everything else I’ve tracked. Users who come back within a week are hooked. Don’t just count feature starts, measure completions. People who actually finish using something stick around way more than those who bail halfway. Session length tells the real story. Quick taps are just curiosity. 2+ minutes means they’re serious. The sweet spot is completion plus return within 7 days. That’s your sticky user right there.