The customer is paying whether or not they use a credit card. However actual businesses have overhead for dealing with physical cash as well. It is slower at

The customer is paying whether or not they use a credit card. However actual businesses have overhead for dealing with physical cash as well. It is slower at the teller, needs to be manually counted and recounted, transported (sometimes with security) and so on. It is not clear whether real costs of handling money are greater or less than merchant fees.