At the same time, US media companies are expanding their range of virtual worlds linked to their children's television shows and online properties. MTV's Nickelodeon recently announced plans to enhance its Nicktropolis site, built around its TV characters, and to create the "World of Neopia" for NeoPets.com, one of the most successful social and gaming sites targeting children aged eight to 17.
Disney, whose sites attracted more than 27m users in March, has created a management group to focus on virtual worlds and online communities. Last year it bought the Club Penguin social networking and virtual world site (slogan: "Waddle around and meet new friends!") for $350m.
Virtual Worlds Management, which tracks
the industry, estimates that there are more than 100 youth-focused virtual worlds either live or in development, with 59 of them aimed at children under seven. As the industry rushes ahead, child advocate groups
are questioning whether parents and other authorities have fully grasped
the explosion in online play for the very young.
"Companies are targeting ever younger children and there is a bigger push to get even preschoolers
online and engaged in social networking sites and virtual worlds," says Susan Linn, of the Boston-based Campaign for a Commercial-Free Childhood (CCFC). "While virtual worlds can be a creative endeavour
for teenagers, there are real problems about their impact on younger children."
Potential threat from sexual predators
In the US and elsewhere, public discussion of virtual worlds has been dominated by potential threats to children from sexual predators and from violent images in online games. The media and toy companies have responded with an emphasis on site safety, with limits on what messages a user's avatar can send.
But Sara Grimes, a communications professor at Simon Fraser University in Canada, says there has been very little attention paid to the commercialisation and marketing elements of digital play, including the collection of data that can be used for advertising linked to online behaviour. "It is easy to get distracted from these issues. The sites also play on that by promoting themselves as safe haven
and tapping into parental concerns," she says.
Last December the CCFC launched a letter-writing campaign against Ganz after its Webkinz site - previously free of advertisements - started carrying ads for DreamWorks' Bee Movie and Fox's Alvin and the Chipmunks . The advertising included offering children's avatars virtual clothing such as bee suits and the hoodies
worn by Alvin and his chipmunk