When quality is hard to judge, price becomes a shortcut.
More quotesRotating offers separate shoppers according to what they can change. Someone following a dinner recipe buys the basil at £2.40. Someone choosing dinner in the aisle notices discounted parsley and cooks something else. The supermarket needs no biography of either customer. Their substitutions reveal enough.
This is surveillance without a camera. The price pattern asks about urgency, storage, mobility, spare time and willingness to abandon a plan. Customers answer by waiting, travelling, switching or paying.
Economists can call the result segmentation. From the other side of the trolley it often feels like a constraint surcharge. Flexible people obtain advance fares and promotional bundles. Those with irregular shifts, caring duties, little storage or limited mobility pay for the practical choices they do not possess.
Comparison tools reduce some of the fog. Clear unit prices make substitutions visible. They do not create a free evening in which to search four supermarkets, place two deliveries and rearrange dinner around a saving. Attention is part of the price even when it never appears on the receipt.
The seller has learned something valuable from two purchases and one refusal. No protected characteristic was requested. No questionnaire needed consent. The signals arrived through ordinary shopping behaviour and vanished into aggregate pricing data.
At the till, the basil scans at £2.40. Dinner remains on schedule. The receipt goes into the bag with everything required by the recipe.