The Facebook and Twitter social networking sites both experienced triple-digit growth in 2009, according to the comScore Digital Year in Review.

Twitter Gets Younger in 2009 As Twitter’s audience grew in 2009, the site experienced interesting shifts in its demographic composition. All demographic segments achieved substantial gains in visitors, but certain segments grew more rapidly than others to gain in terms of their share of audience. The initial success of Twitter was largely driven by users in the 25-54 year old age segment, which made up 65% of all visitors to the site in December 2008, with 18-24 year olds accounting for just 9% of visitors. Read more at www.marketingcharts.com