coupons
The coupon feature of PS3 has been a great add-on. However, it still has a few limitations. For instance, there's no way to give free shipping, apply multiple coupons to the same purchase or multiple discounts to the same coupon. I think if would be nice if you could add say a discount to a certain product if they enter a code and also add a shipping discount. That would probably take the ability to use multiple coupons, but I think it would be a nice addition.