Clicks are a pretty good way to measure engagement of your audience, even if your only goal is just to build brand recognition. If you're showing tons of people an ad, and no one's clicking, it's probably because they DGAF about what you're showing them and the impact is very minimal.

Platforms like Facebook and Yelp definitely will sometimes try to push you to a package which is pay-per-impression, and they have a whole presentation which tries to make it sound like it's worth it, but the times that I've analyzed their performance it's been ridiculously bad. Like, "kind of looks like every click we're getting is an accidental click" bad. I looked at our Facebook campaign for a company I worked for once and we were literally paying $300-500 per conversion with every other part of the pipeline already set up and tested. They just sell you on pay-per-impression packages and then show your ads to a ton of people who scroll past them instantly. In my opinion.