Asheron's Call had a very viable (unofficial) real-money trading system via ebay. I never even played the game but knew some people who did and they made fairl

Asheron's Call had a very viable (unofficial) real-money trading system via ebay. I never even played the game but knew some people who did and they made fairly substantial amounts of money selling virtual crap on ebay. This was before the rise of the hardcore Chinese gold farming industry, in-game limitations on item trading (ala WOW), ebay restrictions, etc.