Your general premise is valid, but the specific theory doesn’t fit the relationship between the merchants and the credit card companies. See the fight over the

Your general premise is valid, but the specific theory doesn’t fit the relationship between the merchants and the credit card companies. See the fight over the Durbin/Marshall swipe fees bill: http://merchantspaymentscoalition.com/merchants-support-senator-durbins-comments-favor-credit-card-competition-act http://merchantspaymentscoalition.com/merchants-support-sena... But your point about support — eg reversibility and fraud prevention — is very valid. Credit cards aren’t merely transactions in databases, but a set of customers and services.