Google said the buyers it contacted in this instance were impacted by invalid traffic over the course of a few months this year, primarily in the second quarter. Part of that traffic affected video ads, which carry higher ad rates than typical display ads and are therefore an attractive target for fraudsters.
Google has also joined a number of industry initiatives, such as the “Ads.txt” project launched in May by the Interactive Advertising Bureau, an industry trade body. The tool lets premium publishers insert a text file on their web servers to list all the ad tech vendors authorized to sell their inventory so ad buyers can confirm which platforms are selling legitimate ads.
“When people talk about [ad fraud], there’s a big specter to it and a big concern about invalid traffic in digital,” said Mr. Spencer. “It’s not that large in terms of a percentage of what people are buying, but it can be a little bit scary to buyers, and our goal is to remove that to improve the trust overall in the ecosystem.”