instead of 20 blogs, just work on single blog hardly. and dont coppy, write original content. you may get the result
More traffic => More views/More clicks. So you should try to get more traffic and then try CPM/CPA/CPC
Work hard to get more traffics to your site. Work on your content (make it unique).Blend your ads with your site template (it may increase your CTR). Make keyword research for your blog (use google keyword). The more traffic you get, the more clicks you will get. With this techniques, you may earn more than $10/d .