I'm not even talking about ads, really. Just item presentation. Making your stock of the exact same item more appealing than another places, or making one brand of an item more appealing influences people to buy that one, as opposed to the other.

The idea is the same with the digital displays. You don't have to worry about what the item itself actually looks like, within reason, it's always going to appear at first glance to the customer to be clearly labeled, bright, fully stocked, and ready to grab.