Your Adsense placement is done really well, I don't understand why you aren't receiving more clicks. The only two things I can understand from this is that either you're keywords are low-paying or you're targetting the wrong countries. What are the top referrers (as countries). Is it USA or India?
That's the problem. Advertisers prefer to pay for USA traffic over than paying for traffic from India, Iran, China etc.. because these countries are so easy to get traffic from and many other economical reasons