Pet Peeve: Applying Promotion Code At Checkout

I have a huge pet peeve that's related to promotions codes.  Some e-tailers are guilty of it and some are not.  My pet peeve is that certain e-tail websites force customers to go through the checkout process in order to apply a promotion code.  This has become an issue now that many e-tailers are offering discount codes with the wording "certain designer exclusions" and/or "mystery" discount codes.  Why is this such a PITA?  Let me tell you why...

Whether I ultimately purchase an item because of a promotion code obviously depends upon the designer exclusions and/or the actual discount of my mystery discount code.  Sdding an item to my cart in hopes that the promotion code is applicable is just a crappy way to shop.  But I can confirm the following: I'm MORE likely to add something to my cart if I know that it is included in the promotion code and/or the actual discount amount of the promotion code.  I'm not a fan of being disappointed.  KWIM?

Forcing me to shop and then create an account to get to the checkout page where I can apply the promotion code is annoying/irritating and more importantly, a waste of time because usually, this is what happens:  1) the designer item that I want is excluded from the discount code and 2) my mystery discount code is the lowest possible discount being offered.  It's unfortunate...but a fact of my life.

So let me be clear on this:  Going through the process of shopping and checking out in order to apply a promotion code will NOT make me more likely to purchase the items in my cart...especially if I find out that the designer item is excluded from the discount code and/or the mystery discount code results in the lowest possible discount amount.  It just serves to PMO.  When I am able to apply a promotion code upfront (i.e., pre-checkout), I'm a happier customer.  And a happier customer is a customer who purchases more items.  Hint.  Hint.