Google charges marketers even when its own checks indicate that adverts were not viewed by human beings, according to researchers.
The experts reported that YouTube did not count many of the “fake views” they directed at their own videos. But it still charged the researchers for many of them.
The case highlighted the need for more transparent analytics, said one expert.
Google said it would work with the researchers to improve its performance.
“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,” a spokesman said.
The experts tested the systems employed by five video platforms, including YouTube.