Facebook overestimated the average time spent by users on its video platform for the last two years. The company recently told advertisers that it had miscalculated the video metrics, which artificially inflated the figures.

"We recently discovered an error in the way we calculate one of our video metrics," Facebook said in a statement. "This error has been fixed, it did not impact billing, and we have notified our partners both through our product dashboards and via sales and publisher outreach. We also renamed the metric to make it clearer what we measure. This metric is one of many our partners use to assess their video campaigns."

According to the Wall Street Journal, Facebook's faulty metrics were artificially inflated because it only counted videos as viewed if they had been seen for three seconds or more, not taking into account shorter views. The miscalculated figures did upset advertisers even as the company is working to rejig its system.

The miscalculation was so high that it overestimated viewing time by 60% to 80%. In view of the error, marketers are believed to have wrongly estimated the performance of the video advertising they had purchased from Facebook for the last two years. Media companies, especially new clients, could be gravely affected as they may have projected inaccurate data about the consumption of their video content on the platform.

Facebook has been trying to promote its platform as a more video-friendly site for quite a while, with the recent introduction of live video.