According to PEW research, some 19% of internet users now say they use Twitter or another service to share updates about themselves, or to see updates about others. This represents a significant increase over previous surveys in December 2008 and April 2009, when 11% of internet users said they use a status-update service.
Three groups of internet users are mainly responsible for driving the growth of this activity: social network website users, those who connect to the internet via mobile devices and younger internet users (those under age 44).
Digital 3000 