It is more of a numbers game in Adsense so I suggest that if you are earning a dollar from a single site why not make a couple more to earn better?
You can reach $100 in just a shorter time if you focus on promoting targeted traffic for your site. Just provide a good and interesting content on your site then submit it to social bookmarking sites.
Option 1) Increase whatever you are doing by 30... Option 2) Replicate the concept and make 30 other websites...
good work man m still trying to hit the 100$ mark every month mostly i would make around 80 to 100 $ BUT on my pregnancy blog, NO security. but congratulation on your success