After reading Outland Bound's amusing tale of an encounter with a level 59 "Recruit-A-Friend" player wearing level 26 pants because of the triple-leveling benefit, I got to thinking about the gameplay ramifications of this promotion. As a marketing professional as well as a student of game design, this promotion seems to me at best a bad idea and, at worst, a game-killer.
As tight as the Blizzard team claims it is, and as much as it professes to act only in the best interest of gameplay, this promotion may have been poorly conceived. It seems like the Marketing Department had a great idea to accomplish two goals: (1) acquire more accountholders and (2) encourage current accountholders to stay. However, I wonder how well this idea was vetted by the game design team. My guess is: not well at all.