Click Forensics has some data out on click fraud (clicks on Internet ads that are not real) in the fourth quarter of 2007 and for the full year. The industry-wide average click fraud rate for the entire year went up 15 percent, ending the year with 16.6 percent of all clicks on Web ads being fraudulent. The click fraud rate for search engine ad networks alone, including Google AdSense and Yahoo Publisher Network, grew even more. That was up 47 percent in the fourth quarter, ending the year with a 28.3 percent click fraud rate. According to this data, nearly one out of every three clicks on a Google or Yahoo ad is fraudulent. While the year-over-year growth is cause for concern, the cli ...