Macy's solves the problem of coupon codes in a way that's good for everyone. They have a coupon code box. They also have a link to a page that shows you all available Macy's coupon's. If one applies to your cart, you can use it. If there isn't a coupon for your cart, you might find out something else is on sale and buy that too. If you don't care about coupons, you can check out and ignore the box.
The customer wins. Macy's wins.