http://www.warplife.com/tips/law/copyright/music/legal-downl...
Lots of people earn money from web advertising by writing articles and essays, but a common mistake is that their articles are not long enough. They only make them long enough so that the ad units look nice next to the text.
What you want is an article that is worth someone's time to read in-depth, and that they will want to recommend to others by linking it from their own sites, from Facebook and the link. Ultimately it was those links that paid off, not the adsense directly.
A problem with making so much money from just one page is that it's fragile; the revenue fluctuated wildly. These days I'm working to build my site by writing a wide variety of articles and essays.
In December I got 38,000 page views. I'm not doing anything right now to monetize the site, just a few affiliate ads for books. I do not yet aim to make money from my site, rather I want to build organic links.
Thanks for reminding me that there is more to money making than just products and services!
Interesting thought.