[CRFSaver]

Interchange is a odd duck. Visa and Mastercard determine how much a retailer pays in interchange. Large retailers (Walmart for example) will negotiate interchange rates with the networks directly. American Express and Discover charge a higher interchange (or as tehy call it discount as it is a closed network) which is why many merchants don't take Amex and Discover.

American Express and MBNA are really the only ones that release interchange. I can't remember if Discover does. It is not required but if they do its usually in a footnote. (MBNA Table 11: Compnents of Total Other Operating Income).

Now you know I have to disagree on being crooked. I think there are some shady practices sometimes but you are already seeing changes from some companies in the industry.