Do all that many people really use the 3rd free bag though? Obviously we have some examples here, but in general, I can't imagine it making all that much of a difference to most flyers...I am not privy to airline data so I may be wrong. I for one have never even needed it, and I typically travel with professional equipment in addition to my personal items such as clothing etc.. What I find more valuable as an elite is the extra weight allowance. It allows me to consolidate my stuff into one bag, and on the rare occasion or extended trip, two.

Seems like those taking advantage of a third bag may be bringing everything plus the kitchen sink...in which case, might as well pay for it or learn how to pack more efficiently.