Originally Posted by
PWMTrav
Every domestic airline except JetBlue oversells, IIRC. AS does it, but is more conservative with it, as best I can tell. Even on this forum you don't see a lot of discussion on VDB vouchers.
I don't think B6 oversells, but they have IDB issues due to equipment swaps (A321 --> A320).
DL seems to have the most VDB, but their IDB rate is very low. They do a good job of getting volunteers.