I think the majority will tell you different things, I believe if you just work on the site and check the keyword through your cpanel awstats you get a better understanding who visited your site and what they are looking for.
true, but that does not increase your clicks, well yeah sure if you get more visitors you get more hits, but there are a lot of tricks to increase the revenue by adsense, like adding pictures next to it, using certain colors etc!
I think those who earn alot of money from adsense have several sites. I would say atleast 5 or more sites. Or they have forums/communities with over 1000 members who are active. Really active.
