[shimon]

AmEx absolutely reams merchants, but it's probably in your interest to use one if you can, because they provide a lot of nice benefits to the buyer. This includes extending warranty coverage, travel and rental car insurance, accepting returns if the merchant won't, and actually having decent customer service if something goes wrong or a merchant rips you off.

What I'd like to see is a merchant that actually splits the transaction cost savings with you, so e.g. if you use a Revolution card, your groceries cost 1% less (and cash saves you 1.5%). This probably violates their merchant agreements with the other card vendors, though.

[noss]

I've asked the Swedish Competition Authority (konkurrensverket) by email why such agreements are legal. A merchant obviously has more to lose by not offering card payments, so they're in the weaker position.

The authority seemed to be uninterested, like they didn't want to do anything that impede the grow of card payments over cash. Cash being quite expensive since it is "robbable".

The price of a product is set with product cost + average transaction cost. If I pay with a card that has a transaction cost under average, I'm paying for the benefits given to owners of cards that have transaction costs above the average.

Hence, I have much to win from getting a card that has a very high transaction cost and gives me many fringes. Merchants see average transaction costs rise...

[brk]

This probably violates their merchant agreements with the other card vendors, though.

It does. There is a clause when you setup a merchant account that you cannot discriminate against one card over another (or, inversely, incent customers to use a particular card).