The AdWords Ad Placement Report
These videos will show you how to generate and interpret the powerful Ad Placement Reports in the Report Center. If you include the Content (AdSense) network in your advertising, you can’t afford NOT to set up this report.
So what do you do with the information? When AdWords released the Ad Placement report, I assumed that they would have to allow advertisers to pick and choose, not just domains and subdomains, but specific URLs (web pages) to show or not show their ads. For instance, I have ads running on several pages in arthritis.about.com. Some are profitable, and some are not:

Currently, AdWords doesn’t let me pick and choose individual pages. I have go with arthritis.about.com in total or not at all. Soon, I hope, they’ll figure out that the extra data they’re providing in this report makes it hard for me to spend money on bad media sub-channels. Google, are you listening?
So what can you do? Right now, use the total impressions and profits from your profitable Content sites to establish a minimum CPM (how much you’re wiling to pay for 1000 visitors to your website). Then you can set up site-targeted CPM campaigns, and at least delete the ROI-negative Content sites from your keyword targeted Content campaigns.