Click Forensics today reported that the overall industry average click fraud rate for pay-per-click (PPC) advertising was 16.0 percent in the third quarter of 2008, down from 16.2 percent in the third quarter of 2007. The rate was 16.2 percent in the second quarter of 2008. The rate of click fraud for PPC advertisements appearing on search engine content networks, including Google AdSense and the Yahoo Publisher Network, was significantly higher than the overall, representing 27.1 percent of clicks during the third quarter of 2008. Botnets made up over 27.6 of the click fraud during the quarter. Click Forensics gathers the data from a network of more than 4,500 online advertisers and agencies.