Google have released a new addition to its Ad Planner service which enables publishers to contribute directly to the site data provided in Google Ad Planner. See below for a small quote from the Google Blog:  

 “The Publisher Center enables publishers to contribute directly to the site data provided in Google Ad Planner. Website owners can specify their site descriptions, content categories, supported ad formats and sizes, and share their Google Analytics traffic data in Google Ad Planner. With shared Google Analytics data, we can supplement our traffic estimates with actual, site-measured data from the publishers themselves. In turn, you’ll have access to more robust and accurate information in Google Ad Planner to make better-informed decisions about which sites to include in your media plans…” 

Read the rest here, or go straight to the Ad Planner Publisher Center.