Wow that is like, SUPER low. I usually get $0.70 - $1.10 for each click, and my site is really small!
Well my answer is same that 50 is so good if u achieved this and you should be happy and must keep you eye on traffic to website, Do optimize you site and think that how you can gain more traffic on your site. As your traffic will high you 50 will be 60 and can be more......