It seems to me that there are only a very small number of credit card network companies with significant market share (e.g. Visa, MC, AmEx).
1) I would have thought new companies would come in and undercut the fees charged to businesses by the credit card companies. Why don't more credit card companies exist and/or have more market share?
2) One could say the reason is that most businesses don't accept more than a few credit card companies. Why is that?
My guess is that is that fraud liability is a barrier preventing small credit card companies from entering. Anything else?
If this is off topic, is there a more relevant StackExchange site for this sort of business/finance question?