i think you are running the image sharing, song, Bollywood, Hollywood actor actress related topics. these topics have low rated ads. but you can get tons of visitors regarding these keywords. so what's the problem? thanks
It also depends on country where the clicks came from ! Use Higher CPC Keywords to get more revenue...
try using image only ads between title and post. align them appropriately. get new adsense code for that.
Today the ads don't exactly fit your site content. Google collects info about the visitor and show relevant ads according to their interests and not always according to your site content. It is possible that your site attracts visitors with interest in low CPC keywords.