The massive audience at Facebook helped it take a top-ten ranking for the first time in ComScore's January survey of the number of unique visitors to U.S. Internet sites and advertising networks.
The Internet research company said Facebook was viewed by 153.0 million unique visitors in January, or 72.2% of the overall U.S. Internet audience that month, putting the site in 10th place in ComScore's Ad Focus survey of U.S. sites and advertising networks. The top spot went to Google Ad Network, with 197.1 million unique visitors, or 93.1% of Americans online, ComScore said.
Facebook's rising popularity has helped it move up significantly in ComScore's rankings. Last June, Facebook ranked 26th in the Ad Focus survey with 141.6 million unique visitors, or 65.9% of the U.S. Internet audience that month. In December of last year, however, Facebook was already on the verge of the top 10, sitting in the 11th spot.
Excluding the advertising networks, Facebook ranked fourth among the top 50 Web properties in the U.S. in January, behind Yahoo sites, Google sites and Microsoft sites, respectively. Twitter, the popular micro-blogging site, was not among the U.S. top 50 properties in January.