Facebook Has Now Revealed Its Fourth Marketing Metrics Problem Since September

Was undervaluing Instant Articles viewers

Facebook has been undervaluing iPhone audiences on certain posts by Instant Articles publishers, per its blog post on Friday. It's the fourth time since September that the digital media giant has owned up to providing marketers with inaccurate data, following up on an admission just one week ago.

The newest problem was brought to Facebook's attention by metrics partner comScore.

"We've uncovered an issue for a small group of Instant Articles publishers that impacts reporting in comScore," Facebook said in its blog post. "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. …We have reached out to affected publishers."

The tech behemoth did not reveal the affected media companies. 

Instant Articles, which were launched last year, are multimedia posts that publishers such as BuzzFeed, The New York Times, National Geographic, The Atlantic, NBC News and The Guardian are employing to offer viewers a faster loading experience. The publishers sell ads against the Facebook format to, in theory, increase revenues.

On Dec. 9, Facebook admitted to miscalculating the number of likes and shares it shows for web links via its API, or application programming interface. It has also been misrepresenting the number of likes and reaction emojis marketers see for their live videos. 

This last pair of problems do not rise to the level of Facebook's higher-profile issues, like conceding that its video view metrics had been inflated.