How Google Adsense Creates Targeted Ads

Everytime you serve up a Web page that contains Google ads, the Adsense script sends a message to the Google Web server asking for ads. This message includes your ad preference information and your unique client ID (something like pub-158753245895453; you can set it in the script code).

The first time Google receives this request, it realizes that it hasn’t examined your page yet, and it doesn’t know what types of ads are best suited for it. Instead, Google sends you a block of generic ads ( or sends back your alternate content, if you choose that feature). Google also adds your page to a list of pages it needs to visit. Sometime in the next couple of days, the Adsense robot heads over to your site and analyzes its content. From that point forwards, you’ll see ads that are based on the content of your page.

If 48 hours has pass and you still aren’t getting targeted ads, there could be a problem. One of the most mistakes is putting ads on pages that don’t have much text, in which case Google can’t figure out what your site is all about. (Remember, Google only considers a single page-the one with the ad unit-not any other pages in your site.) Another potential problem occurs if you put your ad in an inaccessible page. For example, Google bot can’t get to any page that’s not on the Internet - pages on your personal computer or local network. Also with pages that are password-protected. Some Web sites block off robots using exclusive rules. These also stop the Adsense bot cold.