Facebook just disclosed two additional advertising measurement errors. Since September 2016, the company has admitted to 12 errors some of which have directly impacted advertiser billing.
The latest errors affect mobile video ads. Facebook admitted to charging advertisers for out-of-view video ads, and has provided a refund in the form of ad credits for marketers who were affected. Some advertisers are reportedly getting credits worth more than $5,000.
Facebook said it found out about the errors when it reviewed its metrics over the last two months.
One of the errors affected mobile site videos. Videos are meant to stop playing when a video on a mobile device is being scrolled out of view. However, advertising videos continued to play in the background despite the user having scrolled past it.
One of the reasons why the error does not impact too many advertisers is that only 8% of Facebook users in the US above the age of 17 years are currently accessing the site via mobile.
The second issue affects videos within Instant Articles. Specifically, mobile users on Android with slow internet connections may have scrolled past a video before it got to load.
Although both errors have only affected a subset of advertisers and have been deemed less significant than issues back in May 2017, they may lead Facebook to face growing trust issues.
Facebook has taken some measures to ensure advertisers can be confident in the social media’s ad network, including a Media Rating Council audit, and the addition of third-party measurement verification firms like Moat and Integral Ad Science.