you know what the worst thing is. when we were using google adsense on our websites we were getting exactly the same very very low earnings. when we started using adwords to promote our services we started paying immense amounts to google! so unfair!
Your exactly wrong on that one. The reason why people get unfair earnings per click is because they are not creating good quality sites, but just trying to slap something together as fast as possible.
i think the advertisers of the keywords are not many.. thus google can't give you so much ppc... don't blame google, just do research on your keywords again...