The industry, which is largely based in China, currently employs about 400,000 young people who earn £80 per month on average.
Players in the popular online game World of Warcraft acquire virtual gold by fighting monsters and completing quests.
Some simply buy it from a fast-growing workforce employed to play this and other games. 'Playbourers" , as they are called , sell gold or other virtual goods .
In 2007, it was reported by Edward Castronova, an academic studying the economics of online gaming at the University of Indiana, that the real money trade - people paying real cash for virtual items - was worth around $300-$400m. That estimate is surely much higher now .