Even as Facebook closes in on its 600 millionth user, its growth in the United States and parts of Europe is slowing and may be approaching the saturation point, meaning its future increase in users will be ever more dependent on the developing world.
Over the past six months of 2010, about one-quarter of Facebook’s total growth in regular users came from the U.S., but during December, just 5 percent of the social network’s new users were in the U.S., according to Inside Facebook Gold, a data service by the research firm Inside Network. Facebook gained more users in India, Mexico, Brazil, Taiwan, the Philippines and Indonesia than in the United States during December.
Facebook’s U.S. audience growth has decelerated for the past four months, raising questions among analysts about whether the Palo Alto, Calif., social network is approaching its saturation point here, and highlighting Facebook’s need to get people to spend more time on the social network in order to keep its revenue growing. A similar phenomenon is occurring in countries such as Iceland, Denmark and Sweden.
Facebook now has about 146 million regular users in the United States, according to both Inside Facebook Gold and the German-Czech analytics firm Socialbakers. Data from both show that Facebook’s U.S. growth has slowed significantly in recent months, and is on the verge of crossing the point where less than one-quarter of its users are in the United States. Facebook declined to comment on the numbers, which are roughly echoed by Internet tracking company comScore.
“It’s inevitable that in highly saturated countries growth has to decelerate,” said Justin Smith, founder of Inside Facebook, who believes it’s an “open question” whether Facebook is approaching its user limit in the U.S. “You can only get a certain percentage of the population to become active users, and as you…