I had an odd experience with the latest Amex GC promo. I was buying 8 boxes of cereal @ $3 EA, I had one coupon already. So with the first order of (4) Boxes I bought another Amex GC, surprisingly the coupon I already had actually scanned automatically. The next order of only 4 boxes of cereal, which, other than the GC was exactly the same order, the coupon refused to scan....could it be that the coupon scanned because of the GC? I'm tempted to go back and try to use the coupon on just a GC at self check.