Biz Stone tweeted this article today and I found it to be an articulate explanation of why Twitter is so great for meeting new people of similar interests, while Facebook is all about connecting with, as Mark Zuckerberg has frequently said, "friends you already have."
Despite—and perhaps because of—the trivial and by necessity shortened discourse on Twitter, several friendships have blossomed, recently confirmed in person. That description may sound a bit bloodless, but Babbage turns his steely eye upon his own soul and motives, not just those of others.
Twitter enables the sort of chitchat impossible among strangers on email or instant messaging, and outside the scope of Facebook. Facebook's boss, Mark Zuckerberg, often describes his service as a way to connect with friends you already have. Facebook creates circles upon circles of acquaintance, but most conversation is among those already known to each other.
Read more at www.economist.com
Twitter, however, is a different beast. The asymmetry of follower and followee creates a different rhythm, allowing the possibility of falling into conversation with an unknown someone without invading his or her space. It is a simple matter to ignore or block those who you find uninteresting. And people you know and trust outside the electronic realm lead you to their friends, colleagues and family. Likewise, you may be on the receiving end of tendrils of acquaintance. The shared set of relationships and communication among those you know vets new people for you and you for them.