What new data can I see by linking my AdSense account to Analytics?
Once you've linked your AdSense account to Analytics, you'll be able to view your AdSense performance in a variety of different ways. Specifically, you can view earnings based on user visits rather than just page impressions, giving you a more complete picture of the time users spend on your site before clicking your ads. You can also break down your AdSense earnings by user location, browser type and referring source to find out where and how users are reaching your site.
Look for AdSense reports under the Content section in the Analytics navigation sidebar and the AdSense Revenue tab on some other reports in Analytics for a breakdown of your traffic by AdSense impressions, clicks and revenue instead of by page views.