When creating a coupon I noticed this message:
"Note: If the discount value applied falls below the base cost of the order,
you will be responsible for paying the difference between the base cost and
the actual amount collected. Your account balance and credit card may be
charged as a result."
Zenfolio provides the ability to edit price lists in great details, so it is very difficult to be able to tell if a coupon is going to potentially result in charges with some of the products.
I suggest that:
1) There should be a way to say "never drop under base cost", to ensure this won't happend.
2) There should be a tool that tells me automatically if, with any of the prices in any of my price lists, there is the risk of dropping under the base price.
3) When I edit my price lists, I should be warned if any of my coupons could make the new price drop under the base price.
4) There should be a new Coupon value type: "percentage on profit", that is a percentage that is applied to my profit, not to the total order value.