SiteTruth.net posted results for the past 60-days of his AdRater extension, which looks at “advertiser legitimacy for text ads on web pages.”

The report collected 11,355 domains over the past 60-days and showed that about 55% of those were either questionable domains or unknown domains. The break down is as follows:

Verified Site 11.60%
Identified But Not Verified 30.70%
Not Rated Site 21.60%
Questionable Site 36.20%

He said:

Overall, since the last time they ran this study, he said the landscape for these advertisers have no changed much.

I am not sure how valid this study is, but I figured I put it out there.

Forum discussion at Search Engine Watch Forums.