Facebook Global Growth Slows as U.S. Users Decline

Facebooks explosive user growth may finally be slowing down as last month the social-networking leader suffered a drop of users from the U.S., Canada, the U.K. and Russia, a new report from a research and marketing firm revealed.

The data on Facebook user growth could spook some investors who have been anxiously awaiting the Palo Alto, Calif.-based companys initial public offering, which some reports say could give the social network a $100 billion valuation.

According to research and marketing firm Inside Facebook, the Mark Zuckerberg company grew by 11.8 million users in May, down from 13.9 million in April and well off its 12-month average of at least 20 million new users a month.

The report cited a decline of nearly 6 million users in the U.S. in May to 149.4 million -- the first domestic decrease in a year -- and losses of 1.52 million in Canada. Likewise, Facebook lost more than 100,000 users each in the U.K., Norway and Russia, according to Inside Facebook.

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By the time Facebook reaches around 50% of the total population in a given country (plus or minus, depending on Internet access rates in that country), growth generally slows to a halt, the report said. So far, Facebook has been able to make up stalls and losses with big gains in heavily-populated developing countries like Mexico, Brazil, India and Indonesia.

Indeed, Facebook grew its Brazilian user base by 10% in May to 19 million and its Mexican users by 7.6% to 25.6 million, Inside Facebook said.

Still, the surprising drop in more developed markets could give Zuckerberg more reason to push Facebook into China, a move that could give it access to hundreds of millions of new users, but also put it at odds with freedom of speech advocates.

"From time to time, we see stories about Facebook losing users in some regions," Facebook said in a statement. "Some of these reports use data extracted from our advertising tool, which provides broad estimates on the reach of Facebook ads and isn't designed to be a source for tracking the overall growth of Facebook. We are very pleased with our growth and with the way people are engaged with Facebook."

While Inside Facebook figures show a decline in users, other available data paint a more mixed picture.

ComScore (NASDAQ:SCOR) figures show Facebook grew by 3.16 million monthly unique U.S. visitors in May to hit 157.2 million. Quantcasts most recent data show Facebooks unique increased slightly at the end of April.

However, Compete said Facebook fell to 137.9 million monthly unique visitors in April, down from 140.7 million in March.

Further, Facebook said more than 50% of its active users log into the social network on any given day.

Following in the footsteps of LinkedIns (NYSE:LNKD) impressive IPO, Facebook is expected to file for an IPO as early as October or November and the actual offering may come in the first quarter of 2012, according to published reports.