I just wonder what happens when you share a gamepage link on your FB wall. Does it give you a referral when someone clicks on it and becomes member through the link you posted on your wall or does that only work with the global referral link you have?
If not I think this could be something to think about. Give every gamepage a special referral link to share on social media so you get rewarded for it. That way you can convince a specific target audience on your Facebook wall. Most of my friends like simulation games but they don't like action games or MMO's so it has no sense to post links of those games, but if I post a link of a good simulation game they might become interested and start playing through Bananatic. Good for them because they have a nice game they like to play and good for me because I will earn extra bananas.