Our fastest-growing feature was a keyboard shortcut we never documented.

We tracked feature adoption across 6 months. The fastest-growing "feature" was a keyboard shortcut that was not in our docs, not in our onboarding, and not in our release notes. It had been added by an engineer as a personal convenience and shipped without announcement.

Weekly users after 6 months: 3,100. Our documented shortcut with the highest adoption: 900.

Users had found it through a forum post, a tweet, and word of mouth. When we interviewed them, they said they assumed it was intentional because it worked so well. We had been documenting the shortcuts we wanted people to use, and the one they wanted was invisible.

We added it to the docs and the in-product shortcut panel. Adoption rose to 5,400 weekly, and it became the second-most-used shortcut in the product.

What feature of yours is growing without you, and have you looked at what people are using that you did not announce?