Is this the Fall of Facebook?

As Facebook continues to gain more and more users around the world, a recent study done by monitoring site Inside Facebook showed that the social networking site actually lost 6 million users in the U.S. last month. And while the site still managed to gain 11.8 million users worldwide in May, that’s a smaller gain than the 13.9 million users who joined in April and the 20 million gained during some months in the last year. The study also showed that Facebook lost 1.52 million users in Canada and over 100,000 in the U.K. last month.

But Facebook is denying any such losses, saying that the data from the study is inaccurate. “From time to time, we see stories about Facebook losing users in some regions. 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,” reads a recent Facebook press statement.

Whether or not Inside Facebook’s data is accurate, their losses seem miniscule considering the site still gained in net users last month, and has a total of 687 million users worldwide, 150 million of whom are in the U.S. — that’s about half of the U.S. population. And Facebook claims to have seen 21% growth for U.S. users last month, while the U.K. gained 368,000 new users between February and May.

Furthermore, Facebook is seeing actual usage of the site increase. According to their recent report, 50% of Facebook’s users log on to the site on any given day. And time spent on the site is up as well, according to comScore, with the average user spending 25 minutes a day on the site in December 2010, up from 21 minutes/day in December 2009.

So far the idea of “Facebook fatigue”, in which users ultimately grow tired of the site after a while and close their accounts, has not presented itself in substantial losses, though it might account for some. While not necessarily the norm, it is not unheard of for users who first joined Facebook when it was simply a social networking site for college students to ultimately abandon the site after graduation.

While some think that Facebook might be losing users to different social networking platforms like LinkedIn (NYSE:LNKD) or Twitter, many people have accounts for all three sites, and various others as well — in many ways, the services are complementary, or at least different enough for people to use each. Not to mention Facebook is continually adding new features that no other social networking site has, and is even putting itself in competition with media and entertainment sites like Netflix (NASDAQ:NFLX), Hulu (NYSE:GE), and Amazon on Demand (NASDAQ:AMZN) by offering pay-per-view streaming videos.

It seems more likely that, if social networking sites are losing users, it’s because people want to remove themselves from social networking completely. Society has become very dependent on social networking sites as means of communication, and as long as that continues to be the case, these sites will continue to grow. But similar to “Facebook fatigue” is “social networking fatigue” — users are getting tired of all of their communication being in the form of wall posts and Facebook messages. Just as the invention and rise of e-mail bastardized written letters, so social networking sites have done to e-mail, decreasing communication to its basest form.

Facebook might see its rate of growth slow if competition presents itself, maybe in the form of Google‘s (NASDAQ:GOOG) rumored networking site, Google Cirlces, and we may see growth stop at some point when the market has been fully saturated, but will we ever see a mass exodus of users, from either Facebook or from networking sites in general? Ultimately the question is, are social networking sites just a fad like Furby or cargo pants? Or are they just as integral to our daily lives as the internet itself? The continuing success of Facebook seems to ride less on whether it faces competition from other social networking sites and more on whether it can remain relevant.

Update: What is Facebook Worth After LinkedIn IPO?

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