AdWords is Google's flagship advertising product, and main source of revenue. AdWords offers pay-per-click (PPC) advertising, and site-targeted advertising for both text and banner ads. The AdWords program includes local, national, and international distribution. Google's text advertisements are short, consisting of one title line and two content text lines. Image ads can be one of several different Interactive Advertising Bureau (IAB) standard sizes.
Pay-Per-Click advertisements (PPC):
Advertisers specify the words that should trigger their ads and the maximum amount they are willing to pay per click. When a user searches Google's search engine on www.google.com, ads for relevant words are shown as "sponsored link" on the right side of the screen, and sometimes above the main search results. The ordering of the paid listings depends on other advertisers' bids (thus the system is classified as P4P) and the historical click-through rates of all ads shown for a given search. The auction mechanism that determines the order of the ads has been called a "generalized second price" auction. It is a variation of the Vickrey auction.
All AdWords ads are eligible to be shown on 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 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. Google automatically determines the subject of the pages and displays ads for which the advertiser has specified an interest in that subject. The ads show in boxes resembling banner ads, with the designation "Ads By Gooooooooooogle." These content network sites are those that use AdSense, the other side of the Google advertising model.
AdWords is used by publishers who wish to bring traffic to their websites. The biggest competitors are Yahoo! Search Marketing (formerly Overture) and Microsoft adCenter.
The AdWords product was launched in 2000. At first advertisers would pay a monthly amount, and Google would set up and manage their campaign. To accommodate small businesses and those who wanted to manage their own campaigns, Google soon introduced the AdWords self-service portal. As of 2005, Google provides a campaign management service called Jumpstart  to assist advertisers in setting up their campaigns.
In 2005, Google launched a program to certify individuals and companies who have completed AdWords training and passed an exam. Due to the complexity of AdWords and the amount of money at stake, many advertisers choose to hire a consultant to manage their campaigns.
Ad blocking and Adwords:
The ads are displayed on the top or right hand side of the natural search results. The ads are pure text, and thus difficult to block for normal ad-blocking software. However, the Mozilla Firefox extension CustomizeGoogle can remove them.
2. Content network
The search proxy Scroogle allows users to perform Google searches without receiving Google advertisements.
The AdWords system was initially implemented on top of the MySQL database engine. After the system had been launched, management decided to use a commercial database (Oracle) instead. As is typical of applications simultaneously written and tuned for one database, and ported to another, the system became much slower, so eventually it was returned to MySQL.
Ankit Talwar - Web Designer
About the Author: Ankit Talwar is the owner of www.Dead-Yahoo.com. He is a Web Designer.