A recent study (by Nielsen) to determine the biggest and fastest growing social media sites in the U.S. (for the month of September) shows that Twitter is on top. Twitter has shown 343 percent growth since September 2007; as a result of being fueled by loads of press and tie-ins to coverage of the presidential election.
It goes past Tagged, which clocked in 330 percent traffic growth. The site’s most popular with the 35-49 age demographic. Third place is held by Ning, a service for creating community sites, followed by LinkedIn, Last.fm, Facebook, MyYearbook, Bebo, Multiply and Reunion.com.