The first tweet was posted by co-founder Jack Dorsey on March 21 , 2006 . Twitter now has nearly 200 million users posting 140 million tweets a day . Comment:
The first tweet was posted by co-founder Jack Dorsey on March 21 , 2006 . Twitter now has nearly 200 million users posting 140 million tweets a day . It has played a role in events from Charlie Sheen 's battle with CBS to the Egyptian revolution .