It's been a tough week for Facebook (FB) . First, the social media giant came under fire for the fake news that flooded the site during the 2016 election cycle. Now, Facebook has announced that it found some errors in its advertising metrics -- for the second time in the past few months.
Facebook said on Wednesday that it had uncovered several "bugs" which miscalculated the weekly and monthly page reach for marketers' posts and how many times users viewed videos from start to finish. The company has also been overestimating the average time viewers spent on "instant articles," as well as exaggerating a metric called "referrals" which evaluates posts produced via an app or website.
This comes on the heels of a previous announcement in September which revealed that the Menlo Park, CA company had been inflating its video view metrics by factoring in all video views or three seconds or more. This miscalculated the average duration a video was viewed, with ad-buying firm Publicis Media estimating that viewing time was exaggerated by between 60% and 80%.
None of these miscalculations, including that announced in September, have affected advertisers' billing, Facebook said.
Pivotal Research Senior Analyst Brian Wieser said that many advertisers are "quite angry" with Facebook, even though billing wasn't impacted.
"This is not good for Facebook. The first instance of metrics miscalculation was bad, but manageable," Wieser said. "This is just more of the same, but compounded with the fake news problem, it makes advertisers question Facebook and just generally makes the environment less appealing."