http://te-in.facebookwkhpilnemxj7asaniu7vnjjbiltxjqhye3mhbshg7kx5tfyd.onion/business/help/675615482516035
How it's calculated An impression is counted as the number of times an instance of an ad is on screen for the first time. 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.