Advertisers of Facebook Audience Network (FAN) got the opportunity to check the visibility of the advertisement by using third party services — ComScore or Integral Ad Science.
According to Marketing Land, ads in Facebook and Audience Network are considered to be visible if displayed on the screen at least 50% of their area. In Instagram the standard is 25%. In a press-service of the company refused to comment about information and to disclose relevant standards of visibility.
At the moment, check the visibility of advertising using third-party services are only available for video ads with goal views.
Previously that in 2015 Facebook has introduced a new purchase option of advertising, in which advertisers can pay only for 100% visibility of ads.
In September 2016 it became known that Facebook 60-80% inflated average duration of viewing the video.
In November Facebook announced several changes which will affect to the measurement of advertising effectiveness and user behavior. Among them is the update of the metrics, permission to use third-party analytics services and update of the reporting interface and others.
