The scene: M&S West Hampstead self-service till this morning. There are two coupons lying there, same date, timed 2 minutes apart. Coupon 1: £5 off when you spend £50 in the food hall. Coupon 2: £5 off when you spend £35 in the food hall. They are otherwise identical. Which customer gets which offer? I didn't notice which one was mine. Does the machine scan your clothing to judge how poor you are and adjust the offer accordingly?