Twitter's average daily users in the US has doubled since 2011

"As of February 2012, some 15% of online adults use Twitter, and 8% do so on a typical day. Overall Twitter adoption reamins steady, as the 15% of online adults who use Twitter is similar to the 13% of such adults who did so in May 2011. At the same time, the proportion of online adults who use Twitter on a typical day has doubled since May 2011 and has quadrupled since late 2010—at that point just 2% of online adults used Twitter on a typical day. The rise of smartphones might account for some of the uptick in usage because smartphone users are particularly likely to be using Twitter."

Source:  Pew Internet & American Life Project, 31st May 2012

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