PUBLIC MARKS with tags influence & persuasion

I can remember when I was very young that when my Mum was doing the weekly shopping and I was either being towed alongside or sat in the trolley, we would fall prey to the shops clever psychology of putting sweets next to the counter. Usually, I would grab a packet of the sweets with the most colourful wrapping. When my Mum took them off me and put them back on the shelf, I wanted them more. I wanted that exact packet even more...