Thanks for pointing me to the name. These things are gross, and we need to get rid of them ASAP.

The whole spirit of market capitalism is "players are allowed to be relentlessly self-interested but we rely on competition to keep them in check." MFCs clearly undermine competition and therefore undermine the very foundation of our economy.

They exist on the other side of too:

Discover typically charges the merchant lower fees than AmEx does when you checkout at a retailer. However the merchant is forbidden by it's agreements with AmEx (and Visa, and Mastercard) from giving you a discount if you use Discover card.

You'll never guess what I think about credit card interchange fees and the contracts that prevent these prices from being exposed to the customers who could force Visa, Mastercard, and Discover to actually compete on price.

You could word this as "AmEx protects its customers by ensuring stores cannot tack on an AmEx surcharge" and it would be exactly as true as the way you stated it. Two sides to every story, and all that.

Except cardholders are not the same thing as customers. AmEx makes most of its money from merchants not cardholders. AmEx attracts cardholders with low fees and perks, and leverages the resultant large base of cardholders to force its customers (the merchants) to pay higher transaction fees.

Low fees? Amex?

They do make about half their revenue off swipes, but I wouldn't describe Amex as low fee to cardholders. Their flagship card has an annual fee of $695.

That's relatively low fee for a membership-perks charge card. They also offer zero annual fee credit cards.

Pretty much every lender offers some zero-fee cards, and Amex is pretty unusual in having charge cards at all. Amex relies more heavily on annual fees than their competitors in the space - Chase, Citi, Wells Fargo, Capital One...

What lender are you thinking of that makes Amex look low-fee?

Diners club used to be more. They got sold for parts though

If the deal is so awful for the merchants, they can choose not to accept AmEx cards at all. Nobody is "forced." Costco switched to Visa.

This should also be illegal, but one wouldn't expect much movement on this issue during the presidency of "the senator from MBNA".