Google AdWords, Google Mail and other banner and paid online promotions.

Google AdWords is an online advertising service that places advertising copy above, below, or beside the list of search results Google displays for a particular search query, or it displays it on their partner websites. The choice and placement of the ads is based in part on a proprietary determination of the relevance of the search query to the advertising copy.

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 Ad Words ads in response to user searches, but do not affect quality score.

The “Google Display Network” (GDN) (formerly referred to as the “content network”) shows AdWords ads on sites that are not search engines. These content network sites are those that use Ad Sense and Double Click, the other side of the Google advertising model. Ad Sense is used by website owners who wish to make money by displaying ads on their websites. Click-through rates on the display network are typically much lower than those on the search network and quality score for Display Network is calculated separately from Search network.