Facebook acknowledges discrepancy that had overstated a video view metric
A miscalculation in the "average duration of video viewed" has overstated the overall video performance (within this metric only).
If you have been relying heavily on Facebook’s average duration of video viewed metric, you’ve likely been using some inaccurate stats. Facebook has officially announced that the metric has been incorrectly stated due to a miscalculation. Along with the announcement came an apology for the misinformation from David Fisher, VP of advertising and global operations at Facebook.
In a lengthy Facebook post, Mr. Fischer chalked the error up to an invalid equation that generated the metric. The metric should have been calculated by diving the total time spent watching a video by the total number of people who played the video. Instead it used a formula that divided the total time spent watching a video by the number of “views” of a video. Basically, instead of dividing by number of plays, it was divided by the number of “views” (when the video was played for three or more seconds). This error has now been fixed.
Of course, this math led to inflated stats for the “average duration of video viewed” metric. Thankfully, this math error had no impact on any other reporting, and it has had no impact on numbers that Facebook has shared in the past. Marketers, if you have been relying on the average duration of video viewed metric, brace yourself, as lower numbers are imminent. Thankfully, all other metrics are unscathed.
For the apology and explanation behind the error, please see the full Facebook post from Mr. Fisher.