There are plenty of other examples of companies trying to harness the power of virtual worlds. Vexed Generation, a British clothing company, tapped the opinions of the members of Entropia Universe, which was created by the Swedish company MindArk,­ about new clothing styles and inventory in its actual brick-and-mortar stores. "Never before had they had such immediate feedback from the end customer," says Marco Behrmann, chief information officer of MindArk. "They were thrilled and even got a new computer in order to more efficiently talk to the Entropia participants."

Massive Incorporated, an advertising agency recently purchased by Microsoft, supplies ads that appear on billboards inside Entropia. In Second Life, Warner Bros. held a premiere for X-Men 3, complete with avatars who represented Hugh Jackman and Halle Berry and walked down the red carpet. Major League Baseball built a replica of Pittsburgh's PNC Park, the host of this year's All-Star Game, and ESPN did a simulcast of the home-run derby into the virtual world, with avatars who represented sluggers like Boston's David Ortiz and the eventual winner, Philadelphia's Ryan Howard.

All of this may just be a precursor of what's to come. Reuben Steiger, CEO and cofounder­ of the company Millions of Us, which helps businesses understand virtual worlds and take advantage of their possibilities (an indication in itself that the real and virtual economies are becoming increasingly intertwined), envisions auto companies actually letting users of virtual worlds design cars. "They'll have a competition, and the one that is most popular will be a concept car and go into production, hypothetically," he says. "I think it ties into the whole cultural zeitgeist of the wisdom of crowds and the ability to use distributive systems to do things that even the smartest individuals can't do."

While Castronova can see plenty of ways that the virtual and real-world economies intersect, he's far from convinced that companies have much of a clue about how to operate in places like Entropia and Second Life. Even advertising and raising brand awareness, probably the most doable ventures thus far, can be done in a way that is strongly rejected by virtual-world participants. A hard sell is just asking for trouble because, as Castronova points out, people in virtual worlds have complete control over everything, including the advertising message you might be trying to send. "I think few businesspeople understand how empowered users feel themselves to be. They tolerate nothing - nothing - that they don't choose themselves," he says. "Think about the era of TV. It was possible to send an image into the living room and control it. And what is happening with virtual worlds is the image is coming right off the TV and the people are holding on to it, and they can toss it around and jump up and down on it."

Because business executives are just now discovering virtual worlds, it is perhaps not surprising that individuals are responsible for most of the economic activity: In the virtual world, at least, mom-and-pop outfits trounce big corporations. Take the case of Christopher Mead, a 36-year-old former factory worker and a stay-at-home father from Norwich, England. He sounds like just about the complete opposite of a cutthroat businessman. "I came to Second Life because I wanted to get away from conflict and people who put greed ahead of other people's feelings," he says. "I'm no businessman; I'm not constantly looking for ways to squeeze more money or to cut costs."