How Google Adsense works
1. Add a short Javascript script provided by Google to the webpage;
2. the user browses the webpage;
3. the Javascript script says to the Google ad server: "Hey, give me some ads ";
4. The Google ad server replied, "No, who knows what is on your page?
5. the user sees a page without Google ads or with Google public ads;
6. The Google ad server sends a robot to browse the webpage;
7. The server analyzed the webpage content and found that the word "pizza" appeared 20 times and "Washington" appeared 6 times;
8. The server thinks this webpage is discussing "pizza in Washington ";
9. Another user browsed the webpage;
10. the Javascript script says to the Google ad server: "Hey, give me some ads ";
11. The Google ad server replied, "Well, this is a page about pizza in Washington. Here are some Washington pizza take-out advertisements! ";
12. The user thought, "Well, I'm planning to take out a pizza." Click the advertisement;
13. You have made a little money;
14. Recurrence starts from 9th.
Original article: http://gae-django-cms.appspot.com/detail/530001/Google%20adsense%E5%8E%9F%E7%90%86%E7%9A%84%E5%BD%A2%E8%B1%A1%E8%AF%B4%E6%98%8E