The overall industry average went up to 17.1% from 16% in the third quarter, while the average click fraud rate of PPC adverts appearing on search engine content networks, including Google AdSense and the Yahoo Publisher Network, was 28.2%, up from 27.1% in the previous quarter.

The index’s publisher, USbased Click Forensics, said that traffic from botnets (internet- connected PCs which have been compromised and can be controlled remotely without the PC owner’s knowledge) were responsible for more than 30% of all click fraud traffic in the final quarter of last year.

The statistics aren’t broken down by sector so it is difficult to pinpoint how badly recruitment is affected but Steve O’Brien, vice president of Click Forensics, told Recruiter that the click fraud rate tends to be higher for industries with keywords such as the law and insurance.

Tony Jewell, chief technical officer of job search engine Workcircle, said recruitment keywords can be expensive but aren’t at the high end. “Considerably cheaper than lawyers or insurance but more expensive than other classifieds or retail is roughly where I’d put it,” he said.

As a company that sells a PPC service, Jewell is conscious that fraudulent clicks can damage a reputation and Workcircle takes a number of steps to prevent customers being charged for clicks that aren’t from real candidates. “Every morning, before we charge for clicks from the day before, we check the reports from various software — we’re looking for large numbers of clicks from the same IP address or the same user agent
over a short period of time.”

He added that clicks that come at regular intervals or travel through the site in an automated fashion (such as starting with jobs that begin with A) are indicative of software, rather than a person. While in many cases these are not an attempt to defraud, they still aren’t valid clicks. Advertisers can carry out similar checks themselves using tools such as Google Analytics which will help identify any clicks coming from a single geographic location or in a short space of time.

Jewell advises factoring in a degree of risk and focusing on return on investment. “If 20% of clicks are invalid, are the other 80% good enough
for it not to matter?” he said. “If the traffic sends customers who convert, and hence is profitable, then we’re happy.”
www.clickforensics.com/resources/click-fraud-index.html
www.workcircle.co.uk