Sainsbury's have a machine that you can swipe your card in on your way in to the shop to gain discounts on certain items. The theory they gave was that these offers would be based on the customer's spending history. So they offer me alchohol, pet food, children's foods...and I never buy these items. If it wasn't for their habit, along with practically everywhere else I shop, without a card, of identifying the items I buy frequently, even travel to buy, and remove them from their stock, I might think they haven't the slightest idea what I buy.

Penny