Some random idea popped into my head today about the RMAH... My thought was that it could be a way for blizzard to get people to play the game for a longer time with psychology. The longer people play the more expansions they will buy. Any way here is how it would work:
1. Person plays the game for the first time.
2. As the person plays the game they get rewarded with new gear and levels (I think pretty much every rpg out the rewards people with gear.)
3. The longer the person plays the more gear they get rewarded.
4. Person wants to play longer to get more of the rewards.
5. Person reaches end of the game and has all the best gear. No more rewards (most rpg's end here but with the RMAH...)
6. Person starts to get rewarded for farming the gear over and over because it can be sold on the RMAH.
7. RMAH won't keep the person playing for ever but it can keep them there long enough to keep them interested in upcoming expansion where the cycle starts again.
/take tinfoil hat off my head.