At least shoppers with bar code scanners are still visiting stores. What should really be striking fear and terror into the hearts of retailers are shoppers who never set foot in stores anymore, people who, like me, order everything online.
But when you don't go to the store _at all_ there is no way they make a sale.
That's not to say that you should be going across town to save $20 on anything. It might well not be worth the cost in time and fuel. But doing that to get a $20 item free, or a $40 item at half price, shouldn't be any more appealing than doing it to get 2% off the price of a $1000 item.
(It's a serious bug in our wetware that all the above feels so unintuitive to most of us.)
So thats why I wrote that.