Social network shrinkage in the U.K.?

Are our friends across the pond getting tired of social-networking sites?

New figures from Nielsen Online, cited by the Guardian in an article Thursday, suggest that they just might be.

Facebook, according to the numbers, experienced a 5 percent drop in U.K. traffic between December and January--as did MySpace.com. Bebo, a smaller presence in the U.S. but wildly popular in the U.K., saw its unique users drop 2 percent in the same period.

If anything, this could mean that after rapid expansion, social networks have reached a saturation point. "It was inevitable that early growth rates couldn't be sustained, and the larger networks have been plateauing over the last few months," Nielsen analyst Alex Burmaster told the Guardian.

Despite the dip, Facebook has grown phenomenally in the U.K. (and just about everywhere else) over the past year. Nielsen statistics say that even with the December-January drop, the site has grown 712 percent in the U.K. since the same period a year earlier.

Last year, Facebook overtook both MySpace and Bebo as the most popular social-networking site in the U.K. In the U.S., MySpace remains at the top, with Facebook in second place and Bebo lagging behind.