Are Facebook's Promoted Posts worth the money?

It depends on what you're promoting. If you're just advertising like everyone else who most likely promotes their posts, not many people will be interested. If you have a sound effective way to snag your audience's attention and hold it, then I'd say it's worth it.

Advertisements are dominating news feeds even now. So one more really won't attract too much attention.Differentiate your post from all the others (assuming you're advertising).

You seem to have the personality of someone who knows how to make things pop, as well as make the mundane interesting. So, with that being said, promote one of your posts and see how it goes. Make whatever improvements you need and post again. If you don't have any luck, it's probably safe to say it isn't worth it.

-Noah