Which credit card is friendliest to merchants?
Cash is king. PIN-based debit transactions are cheap. In terms of credit cards, a regular (ie. not a gold card) with no rewards has the lowest rates.  Bigger merchants with lots of card volume likely have better deals that make the differences less pronounced.
Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
Which credit card is friendliest to merchants?

### Response:
Cash is king. PIN-based debit transactions are cheap. In terms of credit cards, a regular (ie. not a gold card) with no rewards has the lowest rates.  Bigger merchants with lots of card volume likely have better deals that make the differences less pronounced.