For the fourth time since September, Facebook has reported that the metrics that it provides to publishers and advertisers are inaccurate.
The metrics problem, however, is much bigger than Facebook, publishers involved in the situation say. Reliable and consistent third-party industry measurement systems don't exist, and digital advertising is reliant on these numbers.
"There needs to be a universally accepted methodology across all the platforms," said Geoff Schiller, chief revenue officer at PopSugar.
Facebook said in an updated blog post that it underreported the amount of traffic coming from Facebook Instant Articles viewed on iOS systems from Sept. 20 to Nov. 30. As a result, the numbers it sent to third-party media analytics company comScore, which is widely used as the industry standard, were lower than the actual number.
In turn, it caused overall traffic numbers for affected publishers to be diminished.
"We have fixed the issue and are working with comScore to produce updated estimates for the relevant time periods for the small group of partners affected," Facebook said in the blog post. "We have reached out to affected publishers."
Other past measurement issues reported this year included overestimating video view times, as well as a discrepancy between statistics reported on the Facebook app and internal dashboards.
The Facebook measurement glitch only affected one small segment of numbers on the platform which therefore minimally affected overall numbers, said Andrew Lipsman, vice president of marketing and insights at comScore. He said comScore adds data notes to alert its clients of any discrepancies. It also updates the numbers as soon as it has the information to do so.
For most publishers, the glitch affected less than 1 percent of their traffic coming from Facebook, according to a source with knowledge about the situation. However, nine companies experienced greater discrepancies: The Washington Post, Mic, BuzzFeed, Wired, Entrepreneur, Foreign Policy, Inverse, PopSugar Celebrity and Variety.
BuzzFeed said about 15 percent of its unique visitors access its content through Facebook Instant Articles on iOS. It resulted in 10 to 20 percent less overall traffic reported through comScore numbers compared with its internal numbers, BuzzFeed publisher Dao Nguyen tweeted.
One other publisher estimated that its traffic numbers were up to 10 percent off from its internal figures. However, two publishers said they found comScore numbers to be 30 to 40 percent less than what they had recorded.