According to the Inside Facebook blog, Facebook hit 200 million active users seven months after the most popular US social network hit 100 million users and only 90 days after reaching 150 million. (That’s the power of a site built from the ground up to be viral.)
On average, Facebook has added 500,000 new members a day since late August. 70% of its members are outside the U.S., which I find extremely interesting. Kinda debunks the myth that this social media phenomenon is something businesses can ignore… small, medium or large.
I like Facebook for consumer brands and causes especially, and have found it a great platform on which to blend the personal with a tiny little bit of the professional, or vice versa. (Your mix is up to you - no one should tell you how much of which is okay…)