A recent Business Week article is noticing a trend among the "sweet spot" social media users who've proven to be a gold mine for social network and virtual worlds advertisers. It highlights a trend: average user minutes spent on social networking sites have seen a 14 percent slump over the last four months, according to ComScore -- which also notes that MySpace's 72 million users in October has leeched some, clocking at 68.9 million in December.

Even when you factor in the fact that the userbase of sites like MySpace and Facebook continues to grow, that growth rate is slackening. And what's it worth when they're spending less time?

In our recent interview with Makena's Ben Richardson, he pointed out that one of the big draws of these new formats for advertisers is the fact that the level of user engagement -- translating to time spent viewing ads -- is much higher in virtual worlds and social media than it is with traditional ads. Numerous other folks we've spoken to who are doing work in this space have told us that the era of measuring impact in clicks or "impressions" is over in this arena, and minutes-per-user is the new benchmark.

"What you have with social networks is the most overhyped scenario in online advertising," Specific Media CEO Tim Vanderhook told Business Week in the article. If users, as the article says, can get bored with profile-swapping and tired of ad proliferation, what might that mean for virtual worlds? Given that the latter is still in its formative stages, generally, and many companies are still experimenting, it's not clear that this resistance has quite reached virtual worlds yet -- but we can look to social networks, perhaps, as a barometer for the issues that can be expected to reach our space shortly thereafter.

[Generation MySpace Is Getting Fed Up | BusinessWeek]