It is in-effing-evitable in every. single. mmo. that I play, I will at some point STOP playing the game itself and get wrapped up in the Auction House or Trade Network.
It starts with me accumulating a bit of wealth through playing, then I start gathering mats. Put them on the AH at a mark-down. Make enough wealth to start BUYING UP mats I don't even need, and slowly create a monopoly.
Why? I. Don't. Know.
You know what's fun? Giving yourself a second job online almost identical to your RL one