The service is designed to make web pages more useful by replacing untargeted ads with relevant sponsored links. says it results in an improved user experience and increased revenue for website publishers.
Eric Schmidt, Google's chairman and CEO, said: "Google remains committed to developing services that bring significant value and return on investment to our advertisers, partners and users worldwide. Through superior relevancy and simple design, Google's many innovations connect people to the world's information and enhance the overall user experience of the web."
Launch of the service follows Google's acquisition of Pyra Labs, the firm behind the site Blogger.com.
Google says its approach to advertising stays true to the company's philosophy that relevance matters most to users. Unlike other paid listing services, Google's advertising technology gauges user response by counting click-through rates to determine the order in which ads are shown.
It is intended that users see the most relevant advertising first and advertisers are rewarded with by what Google claims is average click-through rates at least five times higher than the industry average for traditional banner ads.
The content-targeted advertising service expands the reach for Google advertisers by serving ads on a variety of content pages across the web. The service extends advertiser reach, providing users with highly relevant ads, and enables website publishers to earn more from their content pages.
Charter participants in the content-targeted advertising service include Knight Ridder Digital properties such as San Jose Mercury News, Detroit Free Press, Miami Herald and Philadelphia Inquirer; and HowStuffWorks.com.
Content-targeted ads will also appear on .