Not surprised, I checked out the prices of three items on mysupermarket.com before going shopping yesterday - Fairy liquid, Persil washing powder and Heinz ketchup. All were cheaper at Asda; Fairy liquid by a whopping 30%!
I went to Tescos last night and spent just over £100... i got a receipt telling me that my branded shopping would have been 87p cheaper elsewhere and that I could get 87p off my next shop at Tescos!! They obviously compare all their goods with other supermarkets, so why don't they match the prices straight away?
The interesting thing here is that supermarkets only compare prices with other supermarkets. They never tell you that many of their products are a whole load cheaper if you're fortunate enough to have the time to attand a local market. (Oh, and if there actually is one within reach)
Another problem with the 87p Tesco voucher (we had one for 14p) is that they expire pretty quickly, so unless you make a special trip to spend your pennies it'll have expired or you'll have lost it before you can use it