On the other hand, one could argue that neither Visa or Mastercard makes their money off of their websites. Not their marketing (which comes in the form of ads

On the other hand, one could argue that neither Visa or Mastercard makes their money off of their websites. Not their marketing (which comes in the form of ads or mail to your house), or the amount they cut per transaction, or the fees you get when you've delayed payment. As far as I can see, this is true. I might be completely wrong though.