Davide Cushman at FasterFuture blog spot gives us a real example of how not to talk to your customers and how not to use data within a marketing context.
welcome to Tescopoly
A friend of mine recently received a polite but threatening letter from Tesco because she had parked in the car park at their aircraft-hangar-of-a-superstore at Barhill, near Cambridge, for more than the time Tesco had calculated it was reasonable to shop (I think their limit was/is 4 hours).
This is a car park that's shared with other retailers, by the way.
Let's think about that for a moment. Tesco used a camera to record her arrival and departure from this car park, a camera with numberplate recognition - and one which is presumably connected to a computer which can both generate nasty automated letters AND find your home address, based only on your registration number, to send the nasty letter to.
Did you know Tesco had the right to your address simply because you choose to drive into their car park? Neither did I.
Such Big Brother tactics are somewhat predictable and depressing, talking of depression did you also know that people are more depressed shopping in Tesco than any other retail store in the UK?