"The game also supports an in-game exchange system allowing people to purchase in-game gold with USD."
Sooo... what do you suppose we purchase with in-game gold? Is an in-game exchange system with other players or just the company? What's the value of the currency? Is there a limit to server volume? If there's 100,000,000 gold in circulation in week 3, and week 5 there is 1 billion gold in circulation, shouldn't this depreciate the cost on the exchange? Will in-game costs adjust for inflation? Will this be regulated? Will there be tax audits? If gold "drops" in game, is the game "minting currency"? Should I call the authorities right now?
Let's think this through.