Oh well. Keep at it and eventually you will be successful. How long have you been using Adsense? My niche is making money online and blogging tips. I also write about tech news on my blog.
I got 8.92$ for 3 clicks during this month for one of my site www (dot) techacid (dot) com. I was too surprised by seeing this.
I wouldn't get too happy about those keywords because it is very very difficult niche to be successful in. I am working my ass of to get traffic and there are lots of people that do not click on the ads because they are aware they are ads. If I were you I would get into a different niche of keywords because it could be a lot easier.