I have a facebook page that has over 30,000 likes. Each post I put up has around ~500-700 likes, 20+ shares, etc. However, whenever I share a link that brings people outside of facebook, google analytics shows my site gets <10 hits. (I also use bit.ly to track links that are not my own and same results). Funny enough when I tweet something on Twitter (with an account that has ~100 followers) I get roughly 20 hits