There is an interesting piece by Patrick Collinson in the Guardian Money section today, especially if you buy goods and services on the internet:
First the flight was £187, then suddenly it became £212. An urban myth was true
Most net users know that websites place cookies on your computer (it's how they remember your name and address details). But do they somehow track you, raising prices when you return to a website to make a purchase, knowing that you've been there and are interested in the item? I thought this cookies business was an urban myth, but my experience this week tells me otherwise.
Now read on here.