Let's face it: Facebook is getting less personal, less intimate.

Mark Zuckerberg has recently stated that Facebook's mission is to make the world more open and transparent. That's awesome... But open and transparent generally create environments where people are less personal and less intimate.

Open and transparent is what Twitter does naturally, not Facebook. The bulk of Facebook users joined when the promise was still very much about connecting them to people they know in the real world: friends, family, colleagues, old high school friends, etc.... in a private and secure manner. An environment well-suited for personal and intimate social exchanges.

Twitter is natively public; all content published by its users is public by default. This is well understood by everyone who joins. In fact, the goal for most active Twitter users is to get as many random people to follow them as possible. An environment well-suited for open and transparent social exchanges.

This may explain why Facebook has made so many changes over the last year and a half, in response to Twitter.

The world needs both a Facebook and a Twitter. It doesn't need two Twitters.