I was thinking that a centralized coupon system wouldn't make sense, and when I was writing this I was going based on the assumption that the store would have accepted coupons stored in with it's pricing information. That itself seems unfeasable and pretty unmaintainable.. but not as ridiculous and insecure as coding the info into the barcode itself.

I guess part of me just wanted to assume that a system designed around processing transactions would be less susceptible to such low-tech trickery.

Still, the signs upset me. And it's the Sentry grocery store in Whitewater, WI.

Here's why it is a perceived problem.

You hand over your coupon for $0.25 off Kraft cheese. The store turns in that coupon for reimbursement. It will get the $0.25 back plus an 8-cent handling fee. As you said, the coupon either scans or not. But all the bar code does is tell the POS system basic information to make sure you met the purchase requirements and how much cash you are owed. The bar code contains:
- the value of the coupon
- the product code
- purchase qty requirement (1 package of cheese, two packages, etc.)
- the expiration date.

The stores are NOT linked to some "central repository" of all issued coupons. The store has NO WAY of knowing if Kraft actually did distribute that coupon and therefore no way of knowing if it actually will get reimbursed. It already handed you back your 25-cents, so if it is a fake the store just took a hit.

With non-Internet coupons the physical media provides some measure of assurance. It's printed on shiny paper. An Internet coupon is most likely on #20 white paper. A non-Internet coupon is in full color, with high resolution graphics. An Intenet coupon is in black & white and low resolution graphics.

I said "perceived" above. In reality, with some simple, commonsense controls those worries go away. For example, never accept online coupons for "Free" items or an oddly high value.

Well I could go on but no need to write a book here!