> the merchant pays a fee when you use it

You do know that they increase the default price to compensate for the commission they pay to the banks right?

Ultimately the result is:

- the bank mostly is unaffected because it gets the point it gives you from the merchant

- Merchant increase the price that to compensate for the commission

- you are not affected because whatever you get as points you pay back with the increase in price

- whoever pays cash is paying 3% more which goes mostly to the merchant