The pie above shows the basic breakdown of where the money would go for a typical transaction;
1. Issuing Bank
The largest % goes back to the issuing bank (i.e., Chase debit / credit card).
2. Merchant Account Processor
Second is the processor, whomever facilitates the movement of those monies, (i.e. North American Acquiring).
3. Visa / Master Card
Last but not least is Visa, who gets the smallest %. Respective of their work / risk, they really don’t do much, they never touch the money nor do they take on any risk outside of advertising.