Credit card surcharges in London

Dave Birch took this picture at a music shop near London. The store adds a 2% surcharge when customers want to pay with their American Express card.

His blog has these comments: "Since debit cards generally cost shops less than credit cards, why don’t the shops offer you money off if you pay with a debit card instead of a credit card? I wonder if it won’t get a bit confusing for customers when they get to the till in a shop and then have to start a mental calculus to determine which card to present."

Thanks for sending this to me Dave.