Facebook admits it vastly overestimated video view lengths

Social media giant Facebook has admitted it has been overestimating the length of video views on its platform by as much as 80%, according to a report in the Wall Street Journal.


Facebook has been pushing video solutions to clients

The paper cites a letter sent to Publicis Media in the US which admits the site had “overestimated average time spent watching videos by between 60% and 80%”.

On Friday David Fischer, the vice president of business and marketing partnerships, wrote a post explaining how the network had bungled the calculation for average view duration, and apologising to partners.

About a month ago, we found an error in the way we calculate one of the video metrics on our dashboard – average duration of video viewed. The metric should have reflected the total time spent watching a video divided by the total number of people who played the video. But it didn’t – it reflected the total time spent watching a video divided by only the number of “views” of a video (that is, when the video was watched for three or more seconds). And so the miscalculation overstated this metric. While this is only one of the many metrics marketers look at, we take any mistake seriously.

While Facebook had previously only measured video views of three seconds or longer, which inflated the average viewing time, it will now measure views of all lengths, which is likely to see average view times tumble.

The error may have led marketers and media companies to overestimate the performance of their Facebook videos, and potentially skewed the amount of money they spent with the platform compared to other sites and types of content they posted to it.

The admission adds to a debate around the efficacy of ads on sites like Facebook for brands, with features like autoplay and the three second minimum view measurement felt to skew numbers far higher than the number of people actually viewing the video.

A scathing memo from Publicis obtained by the WSJ reads: “In an effort to distance themselves from the incorrect metrics, Facebook is deprecating [the old metrics] and introducing ‘new’ metrics in September. Essentially, they’re coming up with new names for what they were meant to measure in the first place.”


Fischer added in his post: “We know we can’t have true partnerships with our clients unless we are upfront and honest with them, including when we make mistakes like this one.

“Our clients’ trust and belief in our metrics is essential to us and we have to earn that trust. That is why we also give marketers choice by offering third-party video verification options with companies like Nielsen and Moat. We want marketers to measure video with us in the way they feel most comfortable.”

However many agencies have questioned the amount of third party tracking on the site, with Facebook limiting the providers who are able to plug into its data, and the data they have used.

In Australia the debate around the efficacy of marketing on social networks has been driven lately by Professor Mark Ritson. View his Mumbrella360 presentation below.


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