Currently the only thing that can be deposited into your my Wallet are gift certificates. Its not meant for discount codes.

Think of it as the difference between a coupon and a gift card. One is a discount and one is a form of payment.

Say you go to the store and buy a $200 coat with a $25 coupon.. the cost of the coat is $175. You are taxed on $175 and If you return it, you get $175..and the coupon is gone. Thats similar to a discount code.

But say you go into the store and buy a $200 coat with a $25 gift card. The cost of the coat is still $200. You are taxed at $200 and if you return it, you'll get $200 back.