Click Fraud Rate Is 13.7 Percent

Elinor Mills reports that the industry wide click-fraud rate is 13.7 percent. The rate is less at top-tier search engines such as Google and Yahoo, accounting for 12.1 percent. As you step of the tiers the click-fraud rate increases, 2nd tier PPC engines realize 21.3 percent, and 3rd tier PPC engines realize a 29.8 percent click fraud rate. The data comes from the Click Fraud Index.

http://blog.searchenginewatch.com/blog/060418-172804

http://www.clickfraudindex.com/