If you find it challenging, you can imagine what we find it. This Byzantine system of following the bouncing ball around between a merchant down to a consumer and back again is a challenge at times.
Would you agree with the view that essentially cash subsidizes the credit system? Really, when a guy walks in with $100 to the merchant, the merchant gets $100. If he walks in with a cheap card, the merchant might get $99 or $98. If walks in with one of these fancy cards, he ends up with $95 or $96.
The irony of the whole exercise is that cash subsidizes credit. That doesn't sound quite right.