The "problem" being solved is that the manufacturers of the products sold at Walgreens (presumably) profit from their sale, which means there is room for Walgreens (and an accomplice) to shake them down for a fee and still leave everyone willing to continue the relationship.

This is already done through methods like selling prime shelf space (e.g. eye level) but this only works to a certain extent. Cooler Screens and Walgreens are pioneering a new system where video screens and advertisements are used to further manipulate shoppers towards certain products. Manufacturers who play the game are able to maintain their existing level of sales or even slightly grow them, minus the additional rent they are paying Walgreens and Cooler Screens, at the expense of manufacturers who don't play the game.

This could backfire if the video screens both increase store costs (for the reasons you described) and reduce store revenues from upset customers who no longer wish to shop in such a hostile environment. On the other hand, Walgreens is apparently betting that they have capacity to harass their customers without losing too many of them.