So what happens when player 1 decides to play game abc and becomes fabulously wealthy. Then game xyz comes out and player 1 is automatically the best player in the game before anyone has a chance to do anything simply because player 1 has a massive bankroll coming in from abc. This is the real issue with creating a universal currency. It causes you to ruin the integrity of a stand alone game. For example, is it fair if I go run 500 bots on Diablo 2 then trade all those items off for some currency and then trade that currency for all of the best gear in World of Warcraft? (This is currently happening btw and it hurts both games)