An investigation by the consumer group found the schemes run by Asda, Sainsbury's and Tesco, in which customers are given coupons if their shopping would have been cheaper elsewhere, differ greatly, making them of little real worth to shoppers.
The investigation comes after a recent row involving a Sainsbury’s Brand Match ad, which suggested that customers shouldn’t bother shopping around for deals at Tesco and Asda because Sainsbury’s would give you the difference. But, taking deals and special offers into account, it turned out that you would actually save more by shopping in all three supermarkets, and the ASA banned the ad for being ‘misleading.’
Secret shoppers visited the supermarkets to find that, in the majority of cases, each claimed to be cheaper than its rivals.
Which? executive director Richard Lloyd said: "Supermarket price-matching schemes can save you money but we believe they should be taken with a pinch of salt because they are difficult to compare."
