When I had more uptime and spare brain cells I had a few websites going.
One of them, a PC help site, was getting about 8000 hits a day. That site alone made me $500 weekly from Adsense.
I had another which had a list of 100 hints for Vista users.
A single page with a bunch of links, that required zero maintenance and made me $150 weekly from Adsense. I sold the site, with its whole one page and the domain name, for 2 grand to a friend, who is still pulling income from it.
She has no internet knowledge at all, does nothing at all to the site, just gets a monthly cheque from Google. As time goes by, the cheques are getting smaller, the site is starting to show its age and needs updating.
Payment rates can vary even on small sites like mine from as little as 1 cent per click to as much as 10 bucks or more, depending on the advertiser. The ads are chosen and cycled by Google, all you do is include the required script wherever you want an ad, you can even choose the size and style of the ads. Google places ads on websites according to the likely interests of the visitors too, so the ads are quite productive. You get paid every time someone clicks on a link, regardless of what they do when they get there.
With large sites like megaupload, with traffic of hundreds of thousands or even millions of hits a day, the advertising income is enormous. Google is not just a search engine, its actually the largest and most profitable advertising agency/media organisation the world has ever seen.
