Click Forensics reported that the overall industry average click fraud rate was 16.2 percent in the second quarter of 2008, up from 15.8 percent in the second quarter of 2007. The rate was 16.3 percent in the first quarter of 2008. The rate of click fraud for PPC advertisements appearing on search engine content networks was significantly higher than the overall, representing 27.6 percent of clicks during the second quarter of 2008. Botnets made up over 25 of the click fraud during the quarter. Click Forensics gathers the data from a network of more than 4,000 online advertisers and agencies.