Does the Adblock Plus repo on github has details about how it works? [on hold]

I was going through the repo but couldn’t find how adblockplus actually detects the ads in the page. Can I read the code which does the detection from somewhere?

How to make a chrome extention profitable

I have a nice idea for a chrome extension and since I am going to implement it, I want to know how can I make money out of it. I don’t see any point in Freemium model for this extension since it is very lean product. are there any ways to make it profitable? are there adsense like services for extensions? are there any other ways which are less consumer annoying?