Fold it neatly into your wallet, push it into the farthest reaches of your pocket or screw it up tightly and despatch it into the nearest bin?
Well, the days when shoppers took any of these options are gone. Or so the retail multiples would have us believe.
Ever resourceful in the search for media through which to engage customers, Sainsbury's is just one of a number of retailers running promotions on the reverse of till receipts.
The attraction is threefold: an inexpensive opportunity for cross-selling other services (up to 25% off car insurance through Sainsbury's Bank), selling the space for promotions by non-competing brands (two meals for £4.99 at KFC), and localising the promotions. The KFC deal, for example, was localised to diners in Penge!
But there's more to it than that. Data from loyalty cards can be used to more accurately target discounts and promotions.
Tesco recently identified me from my Clubcard data as an above-average purchaser of wine - the average is only seven bottles a year, I swear - and was able to target me specifically with a till-generated voucher for discounted wine. This is further evidence that promotions at the point of payment demonstrate retailers' continued, resourceful and sophisticated manipulation of data.