Both AA and UA have the same deal -in either case a flight is not necessary (so UA did not up the ante - they matched AA, the only upmanship with UA was the chance to get back miles which had previously expired). In the case of Delta, a Delta flight is needed (partner flights do not count either).

Ironically for me, airlines like USAirways and Delta used to be on the top of list for getting partner miles, but now are at the bottom of the list (Alaska, American, Northwest and United have better expiration policies now). Its ironic because for partner miles, the airlines get money upfront (and this was supposedly a big impetus for AA to relax mileage expiration, since for them the partner miles are more than half of all miles awarded).

[This message has been edited by pgupta011 (edited 08-19-1999).]