Twitter has reached nearly 200 million users registered accounts who post 110 million tweets per day as of the January 1, 2011, writes Oliver Chiang on Forbes.
That’s up from 160 million registered accounts as of September 2010 and 95 million tweets per day as of early December
Full article: http://blogs.forbes.com/oliverchiang/2011/01/19/twitter-hits-nearly-200m-users-110m-tweets-per-day-focuses-on-global-expansion/