I’ve viewed the rampant hype — and sky-high valuations — of social networking sites with more than a few questions. In a hyper-connected landscape, how scalable are social networks?

Or more simply, how many networks can one belong to - or how many connections can someone make - before the quality of their interactions falls below the level at which they’ll bother to maintain them? (Hint: I keep seeing the number 150 bandied about, including in the top comment of this Nicholas Carr post)

A recent report suggests social network growth is plateauing, and the copycat social network sites are starting to shutter their doors:

Social Networking Gets a Sanity Check - GigaOM

After years of hype, noise and funding, the social networking sector is finally getting a harsh, but necessary, sanity check.

Today there are numbers out from comScore that indicate plateauing growth for the big two — MySpace and Facebook — in the U.S. Last week, Revision3 canceled “SocialBrew,” an online video show dedicated to social networking. Meanwhile, Monster killed its Tickle social networking service (first reported in April by TechCrunch), following closely on the heels of CondeNast’s shuttering of Flip and Verizon’s decision to close up its virtually unknown network, which had managed to garner a mere 18,000 members. (Verizon has shifted its community to Facebook.)

Of course, plateauing growth isn’t the same as impending doom, though the combination of slowing growth and ongoing difficulties with monetization raise some troubling issues.

The larger question is really this; will the biggest social networks fall under their own weight, only to be replaced by smaller, self-segregating social networks? Will they simply be high-tech versions of the same old message boards, groups and forums that have existed largely since the Internet’s inception?

It’s possible (if not downright likely) we’ll see more targeted groups emerge from the hysteric fog of today’s social networking frenzy. In the meantime, organizations looking to engage with consumers and prospects will best do so by creating their own content, and using that to prime the “user-generated” content pump.

Relying solely on “connections” to engage readers represents wishful thinking taken to an unlikely extreme.

Stay engaged, Tom Chandler.

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