Microtransactions only really work in a TRUELY side-grade driven environment, or heavily design/cosmetic driven environment.
For every item in an MMO that can be bought for a few dollars, that's one fewer notable quest or interesting crafting recipe that could have actually appeared in the game.
Ultimately, we're faced with two implementations: the first would be a little questline where I meet a goblin and, in the end, get a gobby hat; the second would be to make sure my PayPal account has $5 in it. I'll always prefer the former, where I play the game to accomplish things in the game.
Edited, Jan 10th 2013 3:07pm by KaneKitty