Originally Posted by
kartoffeln
Is either one or the other more stingy, sneaky, or worse with their mileage system/just in general? Does United charge a fee and do either of them expire after 18 months?
Delta is the only of the major US carriers where miles do not expire. With the others you need to have activity on the account every 18 months (or so) or your miles are gone. None of them charge a fee for belonging to the FF program.