What's one small takeaway (from building, marketing, etc.) that turned into a big insight?

For me, it was a very simple, yet really insightful thing: enhance what's already working.

We're running a community forum, and our "Changelog" and "Ask the Community" categories performed really well. But after we featured them on the forum's homepage and applied some changes to improve usability, the engagement boosted significantly.

Key takeaway: it's a really good idea to double down on what's already proving valuable instead of always looking for the next big idea.

What obvious things (at first sight) appeared to be a discovery for you?