In December 2008, 19% of adults aged 18-24 were on Twitter, compared to 37% in September 2009. Twenty percent of adults aged 25-34 were on the site last year, compared to 31% now.
"Internet users who already use social network sites such as MySpace, Facebook or LinkedIn are also likely to use Twitter (35%), compared with just 6% of internet users who do not use such social network sites," the study also reported.
