In fact, the trading of virtual property is so lucrative that some big online gaming companies have jumped into the business, creating their own online marketplaces.

Other start-up companies are also rushing in, acting as international brokers to match buyers and sellers in different countries, and contracting out business to Chinese gold-farming factories.

"We're like a stock exchange. You can buy and sell with us," says Alan Qiu, a founder of the Shanghai-based Ucdao.com. "We farm out the different jobs. Some people say, 'I want to get from Level 1 to 60,' so we find someone to do that."

On eBay, for example, 100 grams of World of Warcraft gold is available for $9.99 or two über characters from EverQuest for $35.50. It costs $269 to be transported to Level 60 in Warcraft, and it typically takes 15 days to get the account back at the higher level."

another amazing example on virtual-reality, is there a difference?

They are now even hacking to gamer's computer stealing her virtual money and then sell it...