Just putting down some "nice to have" feature requests, in case you need more suggestions.
It would be really great if the plugin had the following features:
- Gift Certificates: The ability to mail coupon codes that are good for one use, or one email address, that keep track of the balance.
- Coupons that have limited number of uses (so a coupon code can only be used 10 times, for example)
- Coupons that can only be used X times per email address.
- Coupons that apply to multiple instances of the same product in a cart. For example, we issue a $5 off coupon for Item X. Someone buys 2 of Item X, and the total discount applied is $10, not only $5.