A new rule has emerged from the collapse of the traditional retail business model.
Imagine this scenario. You drive your car to the local shopping mall and you park it in a pay zone. You go into a supermarket in the mall and every aisle is full of advertisements on screens as you make your way around the shop to buy food. You notice that the content on the screens changes for each customer depending on his or her gender, stylishness of clothing and age. You sense you are being targeted according to your profile.
When you reach the till, the staff member waves you through saying that the food is all