ashill and javabytes, pile on if you want, but somebody doing a Silver-level volume of flying with Delta isn't likely to be earning SWUs as an American Airlines EXP. Less than EXP (100K miles, 100 segments, or 100K EQP) and AA has flyers buying stickers for domestic upgrades, even.

As for the complaint about YBM fares being required for intercontinental SWU upgrades, this sticky thread covers it:

http://www.flyertalk.com/forum/delta...nt-thread.html