It’s not the ads. It’s not the Insights. It’s not even a feature directly related to Pages. It’s often the little things that make a big difference. That’s why one of the most important Facebook features is the birthday reminder system we use to scrawl quick notes on our friends’ walls.

This year again I was touched by the countless birthday messages I received on my wall. It sounds like a small thing but each time my iPhone buzzed with a new birthday wish from a childhood, high school, college, or adult friend, I felt a special personal connection that’s hard to explain. Other than planning a very large party there’s no place you can ‘see’ such a broad cross section of friends in such a short window of time outside of Facebook. That’s engagement.

The Brand-Driven Insight? What does this have to do with your Facebook Page? Nothing … directly. Indirectly, it’s these these hot triggers that change behavior that make Facebook a truly remarkable channel. As a conduit for these personal interactions, Facebook starts to subconsciously occupy a very special place in peoples’ hearts and minds. I liken it to an updated version of email — where trusted, permission-based brand updates benefit from being seen in individuals’ very personal inbox amidst messages from family and friends.

Sure, Facebook has struggled with privacy issues and is by no means a sepia-toned bastion of sentiment. The user data they are warehousing and selling is sure to give Google a run for its money. But it’s the simple, overlooked user-engagement features like birthday reminders that attract and keep the masses happy, which in turn makes Facebook a valuable place for us build brand-driven communities.

Photo via Flickr user Will Clayton