Facebook has informed advertisers that the company has discovered two new measurement errors. The latest errors mark the 11th and 12th mistakes the company has disclosed since September 2016 and the second and third that impacted how advertisers were billed by Facebook.
The two new errors involved mobile videos, including video ads, that played while out of view and resulted in Facebook incorrectly charging advertisers. The company has informed the affected advertisers that they will be issued credits as reimbursement for the incorrect charges. A Facebook spokesperson confirmed the errors and refunds on Monday.
Facebook discovered the errors within the past two months during a regular review of its metrics and informed advertisers of them and the resulting refunds last week, according to the spokesperson. A couple hundred of the affected advertisers are receiving credits that exceed $5,000, and the errors’ impact among advertisers is said to be significantly smaller than an issue related to carousel ads running on Facebook’s mobile site that was revealed in May 2017 and announced in a company blog post.
The first error affected videos loaded on Facebook’s mobile site. When a person uses Facebook’s mobile site, videos are supposed to stop playing when that person scrolls out of view or opens their device’s browser to another tab. But some videos, including ads, continued to play in the background after a person scrolled past them or switched to another tab in their device’s browser. As with the measurement error that Facebook revealed in May 2017, the fact that this error was limited to Facebook’s mobile site curbed its impact. A small minority of Facebook’s users are considered to access the social network through its mobile site rather than the mobile app. For example, 8 percent of Facebook’s users in the US who are over 17 years old accessed its mobile site within the past 30 days, according to the Audience Insights tool that Facebook provides advertisers.
The second error affected videos embedded within Instant Articles, Facebook’s proprietary, mobile-only article format. For people viewing Instant Articles through Facebook’s Android app while on a slow internet connection, editorial videos and video ads included in the article may take longer to load, leading a person to scroll past it before the video loads. When that happens, Facebook’s app is supposed to load the video in the background but not play it until a person scrolls it back in view. However, the error affected videos that took longer than one second to load, causing them to play once loaded even if they were no longer in view.
While both errors are said to have only affected a small number of users and advertisers, they contribute to a growing problem that has plagued Facebook for more than a year: trust. The more measurement errors that Facebook discloses, the more difficult advertisers find it is to trust Facebook to calculate those measurements. And Facebook’s errors combine with similar blunders by Google and Twitter over the past year to further sow distrust in digital advertising where the automated delivery of ads leaves them vulnerable to computer errors.
Over the past year, Facebook has tried to rebuild any trust it has lost among advertisers. It has opened its ad metrics to an audit by the Media Rating Council, which Facebook said in September should be completed by March 2019. And it has expanded the number of third-party firms, like Moat and Integral Ad Science, that are able to verify Facebook’s ad measurements. While independent verification falls short of the independent direct measurement that some marketers seek — which would have Facebook provide brands with the raw data that form the basis of its measurements — it does have value. For example, around the same time Facebook discovered its most recent errors, so did Moat, which flagged them to the company.