Facebook 'overestimated' video viewing time

Facebook has overestimated how much video people have watched for the last two years, the firm has admitted.

One advertiser suggested that, in some cases, video viewing statistics had been overestimated by up to 80%.

Facebook's analytics are an important tool for advertisers, who use them to work out how much of their video content is being watched.

The social network said the error had been fixed and had not changed how much advertisers paid the site.

'Unacceptable' behavior

The error affected a Facebook metric called "average duration of video viewed", which was supposed to tell publishers for how...