This is a very good point that shouldn't be overlooked. If a promo looks too good to be true, read the fine print. It probably is too good to be true. Rule number one when dealing with any financial institution is The House Always Wins. They aren't going to set up some promotion that allows the players to extract an unlimited profit. Sure, they might throw ya a little bone once in a while - like a 5000 mile bonus - but somehow I doubt they will let you do funny things with the float on a couple hundred thousand dollars on your Delta Amex.