There are two types of Facebook ads- Pay per click and pay per impression. Normally I am running both kinds at the same time for my clients. One reason is to judge their performance and then switch to the more cost effective method. But here is the thing, if you have pay per click ads running and nobody is clicking on them, let them run!
It's not costing you anything, and it's still free exposure. Let's use my favorite example of the ballet flat shoes again (see my post on choosing a good ad photo here). I see this ad every single time I'm online. I think I clicked on it once, but I didn't do anything after that.
If your ads are not performing well with click through rates, try some new ones. But you don't necessarily need to delete the other ones either. All those impressions have a value all their own.