In most cases, optimization in AdSense would mean testing a variety of color, formats and locations for the ad units. However, it is just as important if not more to optimize the content of the site and make it more user-friendly. It is important to know which homepage design your users will respond to. Or which headline will lure the users to spend more and more time in reading the articles. If the answer to the above questions are known, then it will be easier to incorporate elements that will be user friendly and will help the user in becoming more engaged. The more engaged the user is, the more audience for the AdSense ads.

The answers to the above questions are available with the help of Google Website Optimizer, which is a free tool that is available via Google AdWords. It lets you experiment with different kinds of layouts and content for your site. It also lets you conduct either an A/B test or a multivariate test to gauge how different content can affect different users. To learn more about the Website Optimizer, you will need to visit the site and do some reading. You can also attend various free online seminars.