According to Web analysis firm Experian Hitwise, Facebook was the most visited U.S. Web site last week. Facebook topped Google to become the most visited U.S. Web for the week ended March 13. In the past week Facebook accounted for 7.07% of U.S. Web traffic that week, while Google received 7.03%.

This analysis was based on their core domain only. That means study compared only the domains Facebook.com and Google.com. Google-owned sites

like Gmail.com or youtube.com was excluded from the count. When added up traffic on all Google properties like Google Maps and YouTube, the company's sites comprised 11.03% of visits. Yahoo was second with 10.98%.
Web analysis firm Experian Hitwise also measured their growth rate for that week. It shows Facebook's year-over-year growth far outpaced Google's that week. The number of visitors to Facebook spiked 185% compared with the same period last year, while Google's traffic climbed just 9%.

Facebook had never before beaten Google over a full weeklong period, though it has been the most visited site on recent holidays: Christmas Eve, Christmas Day and New Year's Day. Facebook was also the top site on the weekend of March 6-7.
Since Sept. 15, 2007, Google was the No 1 site each week. Google managed to took the crown of No 1 site from another social networking site MySpace.com on that time.

Matt Tatham, director of media relations at Hitwise said, “It shows content sharing has become a huge driving force online. People want information from friends they trust, versus the the anonymity of a search engine.” He also mentioned, “It's definitely a big moment for Facebook, even though they beat by a small margin, we've seen it coming for quite a long time”

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