"Gold farmers" in Asia who stockpile game currencies to sell to MMO players now make up 85 percent of the $3 billion global "third-party gaming services" industry, according to a new report [PDF] from The World Bank Group's InfoDev arm.
That $3 billion figure is from 2009, and includes revenue generated from services such as gold farming (85 percent) and power-leveling (15 percent) for MMO players.
"Gold farmers," or those players who collect in-game currency to sell to other players, should be encouraged, as these services could aid development in poorer countries, the report suggests.
Western players have limited time to collect resources in popular MMOs such as World of Warcraft, and therefore are increasingly turning to other players to supply them with gear and items at a price.
The report says that the supply chain for these goods has developed into a full blown business model, with individuals working together to secure as much currency as possible, and splitting the revenue between a retailer and a "farmer."
It is suggested that around a quarter of MMO players spent real money on in-game items, with some paying significant amounts to help their characters expand more quickly.
Dozens of Chinese virtual item retailers now make around $1 million each year from the practice, with nearly a dozen retailers making as much as $10 million on a yearly basis.
[UPDATE: An earlier version of this story referred to the global virtual goods market instead of the "third-party gaming services" industry. We've updated the piece and apologize for any confusion.]