According to Hitwise, Facebook almost triples its market share of social networking sites with a 194% increase year over year since September 2008 while MySpace dropped 55%.
Meanwhile, according to eMarketer, Twitter’s market share grew 1,170% from .15% to 1.84%, however, time spent on Twitter took a significant hit. The average time a US user spent on Twitter dropped from 36:27 minutes in 2008 to 15:52 minutes in 2009.
Hitwise also reports that US Internet users spent 20% less time on social networks over the same time period.