Big ad buyers and marketers are upset with Facebook Inc. after learning the tech giant vastly overestimated average viewing time for video ads on its platform for two years, according to people familiar with the situation.
Several weeks ago, Facebook disclosed in a post on its “Advertiser Help Center” that its metric for the average time users spent watching videos was artificially inflated because it was only factoring in video views of more than three seconds. The company said it was introducing a new metric to fix the problem.
Some ad agency executives who were also informed by Facebook about the change started digging deeper, prompting Facebook to give them a more detailed account, one of the people familiar with the situation said.
Ad buying agency Publicis Media was told by Facebook that the earlier counting method likely overestimated average time spent watching videos by between 60% and 80%, according to a late August letter Publicis Media sent to clients that was reviewed by The Wall Street Journal.