In March, 61% of active residents--which comScore loosely defines as users who downloaded the software and "participated in some Second Life activity"--came from Europe. So while a majority of the in-world brand initiatives have originated from the U.S., the messages are increasingly reaching an audience on the other side of the Atlantic.

But according to emerging media guru and blogger Greg Verdino, the numbers don't tell advertisers the whole story. "We can't measure virtual world engagement using traditional marketing metrics like scale and millions of impressions."

Advertisers need analysis that reveals the depth of in-world interaction to help make decisions about Second Life's viability as an advertising channel. "We need to measure things like whether users are returning after their first visit, to whether they're forging friendships and buying in-world products," said Verdino, "much more than we need to know the numbers of people that are registered."

Still, as Second Life's user base continues to grow, global brands such as Coca-Cola are including it as a component of an overall social media strategy. Coke's Virtual Thirst, program, for example, uses Flickr, YouTube and Del.ici.ous in addition to Second Life as a way of hitting consumers across a number of different touchpoints.

"It's more than just throwing up a Sim and getting a lot of residents to come. A new marketing paradigm is starting to emerge," said Verdino. "We just need more industry-level research on how well users are being engaged across all of the channels."

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