Twitter is used by 8 percent of American adults who use the Internet, with the greatest use among young urban adults and minorities, according to the Pew Research Center's Internet & American Life Project.
Twitter, which claims to have about 180 million users, is the leading microblog service among casual Web users.
The communication tool allows users to write quick messages of 140 characters or less and blast them out to their followers on the service. The service has become a major marketing tool for businesses, and has capitalized on this to make money by offering advertising-laced tweets.
Pew, which itself uses Twitter to gauge social media, polled more than 2,250 Web users polled in November.
In response to the simple question, "Do you use Twitter?", 8 percent of online adults said they do, with 2 percent doing so on a typical day.