Some people at DigitalPoint Forums are reporting seeing a new tool in Google AdWords that allows you to specify if you want to block your content ads from showing up on "Domain Ads" and "Error Page Ads." Plus you can also block your ads from showing on sites about specific niches.
Currently, on the Tools page, you can click on "Site Exclusion" and specify domains, subdomains, and single directory names that you do not want your content ads to be displayed on. The extra functionality that some people see are the ability to block categories of ads.
One member said:
Instead of excluding individual sites, it appears that I can now block certain categories of site, as well as "Domain Ads" and "Error Page Ads".
This seems like an awesome feature and I am eagerly awaiting more information from Google on this.
Forum discussion at DigitalPoint Forums.
Update: Google called me late Friday to tell me that this is a beta they are running with a select number of AdWords advertisers. They were unable to give me any more information about this beta. I asked for a lot, but all I got was a confirmation that this exists. David at RedFly Marketing is part of this beta and has posted some detailed screen captures of this in action. Check out the screen captures here.