Spies? No - it's retailers who are busy tracking your every move.
You can take away her smooth, glowing skin, her naivety and her carefree chuckle, but you can never completely remove the little girl from the woman.
That's what I realised when I found myself staring in delight at my daughter's collection of mini grocery items her grandmother collects for her from New World. One of my absolute joys as a young girl was collecting sets of things, or even just thinking about perfect sets of things; I remain enraptured by the mini box of fish fingers and the tiny bag of peas, even if the full-sized versions leave me cold.
But they won't make me switch supermarkets, because I believe loyalty schemes are a ruse, however they're dressed up. For example, my local Countdown offers the chance to collect multitudinous stamps that may be transformed into a free kitchen knife. But my desire to have one is not strong enough to make me try keeping a loony toddler under control for five more minutes as the checkout operator laboriously counts out five or six of the microscopic things.
These are the more creative loyalty schemes, but of course there are still the ubiquitous loyalty cards.