In fairness, I've worked at several places that engaged in this practice, and they're perfectly clear that they're paying for clicks that they'd likely get for free.
The theory is that if they don't do this, their competitors buy this ad space and steal some of their organic traffic, and/or that they're just bidding up the cost of that space to make their competitors less efficient.
Now, that theory may not be cost-efficient in practice. But it's not like the marketers didn't understand that someone searching for the name of our app were going to see it in the list anyway.
The theory is that if they don't do this, their competitors buy this ad space and steal some of their organic traffic, and/or that they're just bidding up the cost of that space to make their competitors less efficient.
Now, that theory may not be cost-efficient in practice. But it's not like the marketers didn't understand that someone searching for the name of our app were going to see it in the list anyway.