When I said Google was the easiest way to make money online, I didn't actually say how much :-) Some people would consider £30 a month to be quite good. You don't need to be a nuclear physicist in order to put a few Google AdSense unit on your website. I tried setting up Amazon affiliate but did not make a single penny so I knocked that on the head.
Whenever I visit my own website, or any other website that contains AdSense, they normally follow my browsing history, they don't necessarily display ads relevant to the content on the website. So if this is the case, why is there so much fuss about ads following the content on your site? Personally, I am much more likely to click on a AdSense unit if it shows something I have already been looking for, sometimes they may show a website that I have found that shows exactly what I am looking for.
I heard a funny online interview with the creator of plenty of fish. Apparently the Google AdSense cheque he took to the bank to cash was too large for them. How I would like to be in that position.