Blizzard has killed the auction house in Diablo III. This was the area where gamers could go to buy and sell their mystical gear rather than adventuring for it.
The game is now being rebalanced to deal with the new Loop system. The reason for the removal? Basically people were trading more than they were questing. There's a video below explaining the situation.
"When we initially designed and implemented the auction houses, the driving goal was to provide a convenient and secure system for trades. But as we've mentioned on different occasions, it became increasingly clear that despite the benefits of the AH system and the fact that many players around the world use it, it ultimately undermines Diablo's core game play: kill monsters to get cool loot. With that in mind, we want to let everyone know that we've decided to remove the gold and real-money auction house system from Diablo III."