Facebook is now the second most popular Web site in the United States, passing Yahoo with 133 million unique visitors in January, according to new research.
Yahoo lost the No. 1spot to Google in February 2008, and now sits in third place, according to Web analytics research by Compete.
"It's been two full years since we've seen a shakeup at the top -- in February 2008, Google overtook Yahoo as number one, and never looked back," the research states. "Is Facebook's next conquest the Google traffic throne?"
Facebook drew 133.6 million unique visitors in January, while Yahoo pulled in 132 million visitors. Google still leads the way with 147.8 million visitors, or nearly half the U.S. population.
Facebook is king of the Web when it comes to the amount of time people actually spend online, however.
"In January, 11.6% of all time spent online was spent on Facebook (compared to 4.25% for Yahoo and 4.1% for Google)," Compete says.
Twitter is also on the upswing, according to separate research released this week.
Twitter attracted 21.79 million unique visitors in January, an increase of 9% over the previous month, according to an article in Venture Beat. The traffic increase has mainly been driven by Google, which recently started posting Twitter status updates in search results.