At the 2007 SES New York, Google's Shuman Ghosemajumder responds to the question: (abbreviated) "How is it possible for Google to identify click fraud when an aggressor utilizes rotating proxies?". Shuman responds by discussing the Clickbot A botnet case and how Google deciphered the click fraud in that situation.
This video is courtesy of the StepForth SEO Blog (news.stepforth.com/blog/). Video taken by Ross Dunn, CEO of StepForth SEO Services. Special thanks to Matt McGowan of Incisive Media for allowing StepForth to record this footage.
Great salesman, definitely knows his product.
ceo560 4 years ago