$100 in 25 days is great. How old was your site? And a tip, do not give out your URL or niche as others will do what you did and do it better.
I have earn around $300 a month for one site. I'm going to start 3 more sites over the next few months.
I am currently only using adsense on one of my sites, it is the site I am going to be putting all my effort into over the next few years. Last month I made $5.96 from adsense. Which is up from $4.33 in november, and $3.72 in october. My goal for january is $10, hopefully I can shatter that goal. Right now I am working on link building and getting back into google's index, for some reason I was dropped out of the search engine. Good luck everyone.