How many loyalty cards can a person physically cart around on their person?
It seems that every time you buy another espresso, or donut, or bag of groceries, or book or tank of petrol, someone is trying to reward (and build) your custom with a little piece of plastic or cardboard.
I used to collect loyalty cards too readily. The situation was pretty desperate: for years I even carted around a Spotlight card - how much use do you think a 25-year-old male was going to give that one?!
One day I realised that I had such a fine collection that even when the opportunity came to use one of them, I would inevitably forgot to dig through my stash to find it. It was a bit like the problem of owning the Entertainment book: one would inevitably find the vouchers that could have been used well after the moment had passed.
So there was the reward of loyalty to urge future patronage: a wallet full of punched and marked cards.
These days I only keep one coffee card, and it's stuck to my pinboard in the office. If I'm going to keep any loyalty card, it's got to get used at least once a fortnight.