Combating Click Fraud via Premium Clicks

We propose new techniques to combat the problem of click fraud in pay-per-click (PPC) systems. Rather than adopting the common approach of filtering out seemingly fraudulent clicks, we consider instead an affirmative approach that only accepts legitimate clicks, namely those validated through client authentication. Our system supports a new advertising model in which “premium” validated clicks assume higher value than ordinary clicks of more uncertain authenticity. Click validation in our system relies upon sites sharing evidence of the legitimacy of users (distinguishing them from bots, scripts, or fraudsters). As cross-site user tracking raises privacy concerns among many users, we propose ways to make the process of authentication anonymous. Our premium-click scheme is transparent to users. It requires no client-side changes and imposes minimal overhead on participating Web sites.