http://te-in.facebookwkhpilnemxj7asaniu7vnjjbiltxjqhye3mhbshg7kx5tfyd.onion/business/help/675615482516035
For example, if an ad is on screen and someone scrolls down, and then scrolls back up to the same ad, that counts as 1 impression. If an ad is on screen for someone 2 different times in a day, that counts as 2 impressions. This method of counting video impressions differs from industry standards for video ads.