Google is making AdSense more sophisticated, a goal advertisers have been seeking. You can now control the kind of AdSense ads you read based on preferences you choose.
In the past, the AdSense ads were based strictly on the context of the website you visited. By selecting your preference, you are helping Google AdSense target their advertising messages, thereby increasing clicks for advertisers making their advertising more effective.
You can also choose to opt out of the program and see the traditional AdSense contextual ads.