A bug in a recent version of Twitter’s Android app inflated video advertising metrics by as much as 35%, a person familiar with the matter told Business Insider.
Twitter let advertisers know about the error earlier this week. The company has issued advertisers refunds for over-billing from video campaigns that ran on its social network between November 7 and December 12.
A Twitter spokesperson confirmed the bug in a statement on Thursday.
“We recently discovered a technical error due to a Twitter product update to Android clients that affected some video ad campaigns from November 7 to December 12,” the spokesperson said. “Once we discovered the issue, we resolved it and communicated the impact to affected partners. Given this was a technical error, not a policy or definition issue, we are confident it has been resolved.”
Twitter is under mounting pressure to grow its ad business and attract new users as user growth has stalled and reports of would-be acquirers like Salesforce and Disney backed out of negotiations. The company only added about 4 million monthly active users between the second and third quarters of 2016.