WoW Gold Facts has said that 30 percent of MMO players buy virtual goods and services.
Eurogamer spoke to the anonymous owner of the site, who said that because of the huge size of the market MMO companies should license purchased transactions.
"In my opinion, the industry would be better served if publishers would recognise that lots of gamers - I've heard it's 30 percent of the player base - like the benefits of RMT, and work with credible companies and allow it to happen," he said.
"I don't see why this is not possible. They could make a condition of involvement in RMT that players give them a complete release of all forms of liability."
Currently, the online "black market" of gold buying has an estimated worth of $2 billion. Most MMO companies take a strong stance against this, and have phishing software in place to try to combat companies from messaging players in-game to hawk their wares.