Depends. I don't typically target the links toward anything, because my readership is so varied in interest that I'd only get a few (less than 5) sales on a book, and that's maybe $2-3 total.

I can link to virtually anything on Amazon and tee it up in a way which I'll get, say, 100-200 clicks. If I talk it up, I can get 400, maybe more. (I have one today which is at ~350 and there's a lot of time left on it.) Because of how Amazon's affiliate tools work, I can get 2-3c/click on those (at scale), even if the clicker doesn't buy the item. But I can't do that more than once a week, if that.