When setting up a FB ad, you can obviously target your audience based on their likes and interests. This way it's possible for instance to address everybody who is fan of the Shayari page. What I've noticed, though, is that not every fan page is listed there. Does anyone know if there's a certain threshold like the number of fans a page needs to have in order to appear there?
No threshold applied. It will be listed after it's creation, maybe your page is on the second or third of the search page results. Even with 1 fan the page will be listed in search results. What is the shayari page name
You can ru your ad whether you have a Facebook page or not. You can send traffic to your mini site or blog but sending it to your Facebook Fan Page will be advantages as people tend to trust FB and not worry about being sent to some weird site.