When I'm in a grocery store, a good end-aisle display combats one of three things regarding my relationship to a product.
1. I'm not aware. A prominent design makes sure to alert me to something I wasn't aware of. Like the early pieces for Coke Zero did so well.
2. I'm not interested. A product that I don't regularly choose has done something interesting. Like how I had always skipped over purchasing Elysian beers (for no reason really), until I saw that they had a beer featuring Sub Pop Records.
3. I'm not convinced. This is where I'm making a regular choice among a lot of competitors. Like a bottle of wine. Where a Wine Spectator 90+ ranking hanging off a bottle will surely help convince me to experiment with an unknown brand.
I wonder if the role of most in-store designs are considered in this way before they're built? Sometimes I bet they are. Other times, I wonder.