Google AdSense is a program that enables webmasters like you to display relevant ads on your websites and earn revenue. After a quick and easy set up, AdSense is designed to help you start showing ads on your site that fit in with your audience, while allowing you to earn money from the unique content you've created.
A key factor in understanding the opportunities you've with AdSense is understanding the traffic you've coming to your site. Webmaster Tools and other Google tools, such as Google Analytics, provide you with the insight to identify who your visitors are and where they're coming from. You're working to bring more people to your site and optimize your most successful pages to boost overall traffic. You can use this info with AdSense to display ads that're targeted to your traffic and better suited to match the content on your most successful pages. For e.g., you can use Webmaster Tools to identify how often your pages appear within Google search results. Knowing these to potentially be your most visible pages, you can use AdSense to display optimized ads on these pages.
Google AdSense automatically delivers ads that're targeted to your content and audience. AdSense also allows you to create Custom Channels that help advertisers target certain pages of your website, or even specific sections of these pages. As a Webmaster Tools user you've an advantage in understanding which Google search results guide traffic to your pages. You can use this info to provide more accurate descriptions of your custom channels for advertisers, allowing you to show even more relevant ads to your users. In turn, you can earn more revenue by displaying these more relevant and high quality ads.