Retailers and issuers are still battling over payment –card fees

American merchants paid more than $40 billion to process debit- and credit-card transactions in 2015. 

--

American consumers favour debit and credit cards over cash by more than two to one. But this convenience comes at a cost. The seller is charged a fee for every card purchase: in America, typically 0.5% to 3% of its value. These fees are set by payment-card networks, such as Visa and MasterCard and collected by card issuers, such as Wells Fargo and JPMorgan Chase.  

http://www.economist.com/news/finance-and-economics/21708669-five-years-after-crackdown-federal-reserve-credit-card-industry