In an effort by Google to deliver more targeted advertising, Google is testing a new program that tracks your behavior on the Internet by tracking what type of sites you visit. For example, if you continuously visit financial sites, chances are, you like finance. Google will then show financial ads to you on various websites you visit that run Google AdSense. You can also actually tell Google your interests in the Ad Preferences Manager.

I think this type of targeting system is fairly overdue. Now that Google better understands your interests and displays advertising that is more appealing to you, there is now a higher chance you will actually click the ad.