That's kind of a dilemma for them, though. They have been very successful up until now by distinguishing themselves from all the other cards with extra perks an

That's kind of a dilemma for them, though. They have been very successful up until now by distinguishing themselves from all the other cards with extra perks and a premium level of service. To pay for those perks and that service, they charge more on the merchant end, with an implied value that their members spend more and are worth courting. Now that this trend is shifting, merchants aren't seeing the value in accepting an expensive Amex card, and are deciding to go without. But Amex still needs something to separate them from the rest of the pack, lest they become just another commodity card. Once that happens (and the merchant network is slow to adapt), users may just switch to the Visa or MasterCard they're already carrying and forget about Amex altogether.