One more clarification, Ajeh. I'm meaning to say that for this rewards program, the gift vouchers would be completely managed on our end, in admin. They wouldn't be purchased by customers. We would be using Zen Cart's gift voucher management system to manage this accrual of "free cash" that could be used anywhere EXCEPT for in the category for drop-shippers.

That's why I still wanted to also offer "normal" gift certificates, where a customer can purchase them for themselves or someone else, to be used as cash.