This report by Pew Internet is based on the findings of a daily tracking survey on Americans’ use of the internet.

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.

Portrait of a Twitter user: Status update demographics (Fall 2009)