Sunday 11/15/09: "Do not double" doesn't mean anything

As I wrote yesterday, you should shop at a store that will double your coupons. But what about a coupon for 50 cents that says "Do not double" on the top? Doesn't mean anything. A store that doubles coupons will still give you the bonus amount. I *think* the difference is that in one, the manufacturer pays the doubling, and in the other case, the store does, but regardless of the reason, be assured that your store will still double a coupon 50 cents or lower if it says "Do not double" on the top.