A General question for all begineer in Google Adsense and its also a basic reason for banning new account or accounts which are ready to pay out.
Actually Google Adsense really loves Content of your website. If your site is well-placed and filled with UNIQUE content then much more earnings can be made easily. Keywords also play active part along with Description of your site.
If you want to increase your Monthly earnings of Google Adsense then i suggest to develop fine piece of Content for the site. The CTR of your can be raised according to the keyword.