Google has been accused of charging advertisers for YouTube clicks against adverts even when some of those ads have not actually been viewed by a human, according to a study.
The paper – Understanding the detection of fake view fraud in Video Content Portals (PDF) – by a group of European researchers evaluated the performance of the fake view detection systems of five major online video portals.
The authors used software that runs automated tasks over the internet to view the videos.
It found that YouTube’s detection system "significantly outperforms all the others" but that it may still be susceptible to simple attacks.
"In practice, this means that views identified as fake and discounted from the public view-counter are still monetised," it found.
According to the research, online advertising was worth $49bn (£32bn) in 2014 in the US alone.
Given its size, it is no surprise that online advertising attracts fraud. Current estimations indicate that 15-30 per cent of ad impressions are fraudulent, leading to losses in the order of billions of dollars for advertisers, said the paper.
"While YouTube is shown to strive to protect its users and clients, for example by reacting quickly when suspicious behavior is identified, we speculate that its setup seems to place an unnecessary burden of risk on clients," said the research.
"For example, fake views can be discounted equally for public and monetised counters, but they are not," it added.
It concluded that the detection mechanisms deployed by video hosting portals was complicated as it currently relies on the companies' own systems.
"In this context, the development of independent tools able to monitor and audit the fidelity of these systems are missing today, and needed by both industry and regulators."
A YouTube spokesperson commented: "We’re contacting the researchers to discuss their findings further. We take invalid traffic very seriously and have invested significantly in the technology and team that keep this out of our systems. The vast majority of invalid traffic is filtered from our systems before advertisers are ever charged." ®