They could easily change the policy by making it so that the website/online vendor has to have that offer currently on the website. Surely all these stores have computers hooked up to the interwebs they can check so a quick amazon search and job done, they verify it is legit and honour it.
John Lewis has a price matching thing that also does online for high priced electronics however it checks it for you over a day or so then once it confirms it, asks you to come in whenever you want to redeem their matched price.
Hmm, pie.







