AdWords distribution

All AdWords ads are eligible to be shown on www.google.com. Advertisers also have the option of enabling their ads to show on Google's partner networks. The "search network" includes AOL search, Ask.com, and Netscape. Like www.google.com, these search engines show AdWords ads in response to user searches.

The "content network" shows AdWords ads on sites that are not search engines. These content network sites are those that use AdSense, the other side of the Google advertising model. AdSense is used by publishers who wish to bring traffic to their websites. Click through rates on the content network are typically much lower than those on the search network and are therefore ignored when calculating an advertiser's quality score.

Google automatically determines the subject of pages and displays relevant ads based on the advertisers' keyword lists. AdSense publishers may select channels to help direct Google's ad placements on their pages, to better track performance of their ad units. There are many different types of ads you can run across Google's network, including text ads, image ads (banner ads), local business ads, mobile text ads, and in-page video ads.

Google AdWords' main competitors are Yahoo! Search Marketing and Microsoft adCenter.