Originally Posted by drewguy

I agree it's goofy. At some level, any airline should be willing to move a passenger to an open seat on an earlier flight for free, at least on a standby basis, instead of letting the seat go out empty, because it frees up a seat they have more time to sell or use.. But they don't, because a general policy of allowing that would mean may fliers could circumvent various limitations (whether advance purchase, or lower fares for later flights), reducing profitability. Of course, UA provides a limited exception through SDC, but they apparently have decided that leaves them with enough control.