"There are now more than 200M monthly active @twitter users. You are the pulse of the planet. We're grateful for your ongoing support!"
Twitter had hit the 100 million mark in September 2011, and as of spring 2012 was boasting of 140 million. Facebook, by contrast, currently claims on the order of 1 billion active users.
All those Twitter users now generate 1 billion tweets every two-and-a-half days, according to Twitter.