Do you have google analytics or a similiar script installed on your website? Check where the traffic comes from. You need quality traffic. And as jackburton above said look for a second monetizer, textlinkads is good.
what? textlinkads? but google hates paid link right? Do you think it's still good? Anyway, I don't know about my traffic but I think I have only small amount of traffic from Search Engine. I am looking for competitive keywords which I believe will be very useful for the long term. Anyway, what is other source income beside adsense and textlinkads?