Yahoo Search Marketing has a very sophisticated Click Protection System that is designed to detect click fraud. We receive billions of searches per month which lead to several million clicks onto advertiser listings each day. We strive to ensure that our customers are satisfied with their advertising experience and work to maintain productive and active relationships with advertisers. As part of our effort to maintain advertiser satisfaction, we utilize the Click Protection System, which includes sophisticated software that evaluates each of our advertisers' clicks.
Our Click Protection System uses search and click data to make both rules-based inferences and pattern recognition-based inferences about which clicks constitute click fraud. While the details cannot be disclosed, the core mechanics involve many data points.
If the data points indicate click fraud, our Click Protection System software marks the identified click in our billing system, and the advertiser is not charged for it. However, the advertiser still receives the click through and we are therefore unable to remove the click from the advertiser's own Web logs. That is, you still get the traffic but you are not charged for it.