This must really be the key. I always asked the same question as the OP because to me it seems like a back asswards way of doing business. I remember reading somewhere that it costs 10 times the amount of money to get a new customer than to keep an old one (marketing ads, commercials, promotional incentives) so if anything it would make sense to give at least equal incentive to customers to stay. If all existing Amex plats leave when their annual fee comes due but they get half as many new subscribers is this really growth?