Hello, I am managing a Facebook fan page related to Cosplayers (as well as other Entertainment related content). The page is has nearly 6,000 fans and growing. It is fairly active and is also linked to a twitter (about 400 followers), so post will also be tweeted. The post will be pinned to the top of the page for 24 hours. It can be a link, picture, video, etc. as long as it is suitable for a 13+ audience. Price per post is $1 Some stats: If you have any questions feel free to ask!
It really depends on what the URL is about. The more closely it appeals to the demographics, the better it will do. I haven't done much tests, since this is a newly created page. But about a week ago, I put up some links which have gotten between 20-30 clicks. Those links had some relation to the page as well. I would imagine more clicks now since the page has gotten bigger but without knowing the nature of the URL, I can't really give much of an estimate. You can PM me if you have more specific questions.