What percentage of credit cards in the U.S. and Canada pay 1-2% in cash back or have reward points/miles? If the answer is most credit cards, then it seems to follow that merchants are being charged 2-3% for most transactions. Or am I missing something here?
Furthermore, I don't believe that merchants are allowed to pick and choose which credit cards they'll accept based on the fees. That is, if a merchant says that they take Mastercard, they have to take any brand of Mastercard. They can't refuse a Mastercard that gives cash back (and how could they even tell at the time of the transaction anyway?).
The typical workaround, which isn't against their rules, is to offer a discount for paying in cash - I can't recall the last gas station I saw that didn't do this (for gas at least), and a number of restaurants also offer cash discounts.
The class action lawsuit was settled in principle back in 2012 and approved by the district court in 2013, but was thrown out recently by the Second Circuit.[3] It would have been the largest class action settlement in history, but many large merchants objected to being bound by a settlement that they had no part in negotiating.
[1] http://www.lexology.com/library/detail.aspx?g=a2722e0c-e0a6-...
[2] http://www.reuters.com/article/us-american-express-antitrust...
[3]http://www.wsj.com/articles/visa-mastercard-class-action-set...
This is illegal in ten states: http://www.creditcards.com/credit-card-news/credit-card-conv...
But that's just interchange (the amount paid to the issuer); merchants also pay a network fee and usually additional fees to their acquirer.
Those differences in credit card fees between rewards and non-rewards often aren't being passed on to the merchant, though, especially small businesses who have little room to negotiate.
Merchant service providers have been pushing this "interchange-plus" pricing model to win over businesses from other providers with the old "tiered rates" pricing for many years now. Even "tiered rates" did pass on some of the price differences, just not as directly.
PayPal/Stripe's model of a single flat fee for all card types is pretty much exclusively an internet (card-not-present) thing, except for the rare coffee shop with one of those Square smartphone dongles. None of the B&M stores you shop in are likely paying flat rates. Different cards cost them different amounts of money.
The biggest merchant ripoff going on right now are processors that charge the same rate for debit and credit. If more merchants knew how cheap debit can be there might be more steering.
[1] https://usa.visa.com/dam/VCOM/download/merchants/Visa-USA-In...