On a similar note, what happens if you buy something and their e-commerce software glitches and over-discounts you for a coupon?
I ordered an a/v rack, and I had both a free shipping and a $50 coupon code. I was under the impression that you could stack them, but after entering the free ship code it wouldn't let me enter the other. So I pressed "Back" and entered the $50 off code instead.
Instead of overwriting the old code, it not only stacked them but factored in the free shipping TWICE, giving an extra $21 off (my "shipping cost" was -$21.00).
I didn't really think about it until the next day when I got my order confirmation, and even then I figured they'd give me call if there was a problem. Nope, they shipped it and mailed me a printed order statement separately.
Part of me wants to call them and at least tell them that they over-credited me $20 for shipping, but the other part of me is telling me to keep the good deal to myself.