Last week, the company made the shock admission that it had been overestimating the average time users spend watching video ads on its platform for two years.
Despite assurances that the error did not affect billing clients, marketers, media owners and agency leaders have expressed serious concerns over transparency.
The error affected the "average duration of video viewed" metric, which was supposed to tell publishers how long, on average, people had watched a video. However, Facebook made a mistake in not including viewers who had watched for fewer than three seconds. This, in turn, inflated the average viewing times for videos. Publicis Media, for example, was told its views were boosted by 60-80%, according to The Wall Street Journal.
Facebook has since revised the metric to "average watch time", which will measure all video views. But Paul Troy, chief marketing officer at Confused.com, called this "ironic". He said: "Digital media claims to be the most measurable medium ever but, time and time again, it is shown that this isn’t actually the case. No-one knew because no-one is measuring either the delivery or the business output."
Simon Daglish, ITV’s deputy managing director, commercial, suggests that there should be a national third-party verifier, similar to how TV audiences in the UK are independently measured by Barb.
Daglish said: "You could have a national basis for verification. Campaigns can be booked internationally on TV but each country has its own measurement system, which is related to how TV is bought in that country."
News publishers also think brands should be able to see how their money is being spent. Dominic Carter, chief commercial officer at News UK, added: "Doubts around measurement, especially in the digital space, are arising on a daily basis and are causing advertisers to question whether the promises made by some players are too good to be true.
"As this market continues to grow and mature, we’re seeing a recalibration of the gold rush as people begin to better understand what’s really on offer."
On the specific issue of average viewing time, media agency specialists claim it is not as crucial to advertisers as other metrics but that the controversy highlights the wider problems with trust in digital media.
George Constantinou, digital trading director at Publicis Media Exchange, believes the viewing-time metric "is only one light on the dashboard" and is essentially a tertiary measure. For Constantinou, Facebook is more of a performance driver and therefore the key metrics are reach and frequency of audience.
The controversy is an opportunity to take a wider look at how data is measured across all digital platforms, according to Sue Unerman, chief strategy officer at MediaCom. She also questioned the creative execution for ads shown on Facebook. Unerman asked: "How often do [creative agencies] present ideas to clients using a mobile screen?"
However, MullenLowe UK group chief executive Dale Gall stressed that his agencies do present ideas on mobile. He said: "It’s not about the time length, it’s about what people thought they were buying versus what they were getting. But if you mark your own homework in a stressful and complex business environment, you’re going to make mistakes."
Despite the controversy, Facebook is better than other tech giants at verification, Andrew Warner, vice-president of marketing at Monster, said. He cited Monster’s beta partnership with Moat, a third-party verification program, although no case studies have been released so far.