Facebook's traffic now accounts for nearly 59 per cent of the US social media market, compared to just under two per cent for microblogging site Twitter.
But while Twitter lags behind Facebook in market share, it has experienced growth of 1170 per cent year-on-year, according to internet measurement firm Experian HItwise.
According to the latest Experian Hitwise report, US visits to Facebook increased 194 percent in September 2009 compared with September 2008. Experian Hitwise measures traffic to 155 social networking websites.
Facebook's share of social media traffic is now twice that MySpace. Others in the top five for market share are Tagged and MyYearbook, with 2.38% and 1.05% share respectively.
In terms of time spent on social sites, MySpace comes top, with users spending just under 26 minutes on the social site.
Experian Hitwise notes a considerable shift in the demographics of social media site users. While a large proportion of MySpace and Facebook users are still in the 18-34 years old cohort, there is a decline in this user group since last year.
The over-55s user group increased their representation on MySpace by 26 percent and 108 percent on Facebook. Approximately 13 percent of Facebook visitors, and seven per cent of MySpace visitors are ages 55 and up.
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