How do affinity credit card comapnies work(ie Wells Fargo, Citi,
Chase)? But, in order for the merchants to be paid for their services,
who pays them and how do the credit card comapnies get their money?  
I know that they make money off of purchases by consumers, insurance
products, and by interest rates.   Is it the same principal like
banks; where they make money off the interest rate gap between
deposits and loans? But, in this case, (hypothetically speaking)CC
comapnies make money from loans they recieve to pay off merchants and
the payments they recieve from the customers?
I know for instance that the basic model for a bank to work it that
they make money off of the interest 'gap'