Google reads the page, so naturally sometimes the ads displayed can vary. On the frontpage, the google ads are worth very little. Ebay and alike. I don't any money for that, in the $0.0X rate, sometimes $0.XX, but rarely. However, move further in and there are higher click through rates, such as with the legal page and alike. I don't have a great click through rate anyway, in fact, my click through rate is awful.
On Chitika, I use keywords from technology, as that's what suits them best. The best paying ads from Chitika are from technology, like i-pods, cell phones, gaming, and alike. But, as my audience is predominately a male, teen audience, it's helpful.
On average I get about 300 views a day and around 12000 pages per day according to Awstats. They are rough averages though. I'll probably get about 0.14% click through rate. Although that can amount to a "couple" clicks a day. Google I've not really been monitoring since I've put Chitika in the more predominant place for the moment until I've satisfied my curiosity with them.
I don't depend upon the google/Chitika ads to pay the server bills, as I've got another set of ads that pay them for me. However, it'd be nice to make a profit.
I've only got the ads on one site at the moment,
http://www.raurusreturn.net , as the other sites I'm developing don't get enough hits to warrant any ads being placed on them at the moment.