Originally Posted by martin33

You make a good point that they may well expect to lose some. I don't see a lot on the gain side. If you're on AA or UA as top tier, and you fly on the sort of Y/B fares that DL SWU's would tend to apply to, you already have deep discount upgrade privileges with miles-- no need for SWU's at all for those flyers. On UA, the cheap miles privilege applies on a host of *A partners as well. Also on UA, you can use their SWU (or will be able to soon) on deep discount Business and upgrade to 3-class First-- a move AA has not matched, at least so far. How would such flyers ever have incentive to hear about, much less contemplate switching to, DM on DL?