While Facebook has only just over taken Google with 0.03 percent more traffic, it is still significant, and looks to increase in the future. In the past year Facebook member numbers have doubled to about 400 million.
Facebook.com now accounts for 7.07 percent of all US web traffic according to Hitwise, while Google.com is the destination for 7.04 percent of traffic. But there are a lot of variables in the study which Hitwise do not appear to have taken in to consideration.
For example, the research does not take into account regional sites, so google.co.uk or google.ie or even google.cn were not counted. It also did not count other Google owned sites like YouTube. The survey also doesn’t include users referred directly from browser searches.
Speaking of google.cn, 27 Chinese advertisers have sent Google a letter calling for talks over compensation for possible loss of business if Google shuts its Chinese site down.
The advertisers are angry that they have not been consulted since the search engine announced in January it was considering pulling the plug on google.cn.
A copy of the letter was posted on the website of state-run China Central Television (CCTV).
"The only thing we can do is to wait - in unbearable agony and anxiety," the agencies said in the letter.
"If Google tells us now that we, our clients, employees, and investors have to bear the commercial risks of their business move... we absolutely cannot accept it!" they said.
Chinese censorship means that, as of October 2009, there were just 14,000 Facebook users in China.
American social networking users spend about six and a half hours on social networking sites in December 2009, according to a study by Nielsen.