Virtual worlds make their money very differently from social-network sites – mostly from selling virtual objects. Though Disney’s Pixie Hollow and Webkinz and Webkinz, Jr. sell real objects such as “friendship bracelets” and plush toys, the economies of most virtual worlds (and multiplayer online games) rely on objects and artifacts such as clothing, furniture, and other property. Social sites, which to date have focused more on display ads, too, are moving into virtual-object retail (see this about Hi5 selling virtual gifts). A figure cited by The Economist indicates everybody may be moving in this direction, though there’s much to be learned about this business model. The article mentions that users at a popular VW aimed at teens, Gaia Online, “spend more than $1 million per month on virtual items.” Gaia recently hired a full-time economist, The Economist says, “to grapple with problems that are well known in the real world, such as inflation and an unequal distribution of wealth” (maybe child psychologists will need to employed too!). The British news magazine otherwise paints a more measured picture of virtual-world popularity than do other news outlets, but the figure it cites is “regular visitors,” not overall registered users. “In America, nearly 10 million children and teenagers visit virtual worlds regularly,” it refers to eMarketer as finding. Virtual Worlds News earlier cited data from Strategy Analytics projecting an overall global population of 186 million now, growing to 640m by 2015 (users of all ages – I blogged about that here). My most recent post on VW population is here.