StumbleUpon sends more traffic to US websites than Facebook

Source: StatCounter Global Stats – Social Media Market Share

For months, Facebook has been the biggest social media site that drives web traffic in the United States. Those days are over– for the moment, at least.

Web discovery engine StumbleUpon is now the biggest traffic driver among social media websites in the US, according to global web analytics service StatCounter. The company unseated Facebook at the top during June 2011, according to the latest StatCounter social media data. StatCounter tracks hits to over 3 million websites, and its social media data is gathered by analyzing every hit referred by a social media site.

This is certainly not StumbleUpon’s first brush with Internet fame. The company, which finds and recommends relevant web content, was originally founded in 2001 and sold to eBay (s EBAY) for $75 million in 2007. But like so many big M&A deals, the acquisition did not go as smoothly as hoped. In 2009, StumbleUpon co-founders Garrett Camp and Geoff Smith bought the company back along with a group of investors.

In the two years since then, the company has been working quietly and diligently at its comeback. StumbleUpon closed on a $17 million funding round in March to expand its product offerings to the mobile and television spaces. The company has also been working on its revenue strategy, with the development of a “paid discovery” offering for advertisers. StumbleUpon briefly surpassed Facebook in StatCounter hits for two weeks back in February, but Facebook quickly regained the top spot.

This time, StumbleUpon’s turnaround is gaining traction at exactly the same time that Facebook’s new user numbers are reportedly slowing down, and Twitter seems to be dealing with stickiness problems. Clearly, something about StumbleUpon’s strategy is working very well. It remains to be seen how long StumbleUpon can retain the top spot — its competitors in the social media space aren’t known for going down without a fight.