VAST Impressions vs. Requests
Due to the way VAST requests are made, the impressions and requests we track in AdButler will not always appear consistent. This can be a result of a number of factors:
Bidding setups will request a batch of ads at once, but then only decide to display a single ad item from that batch. The ad server still has to respond to the request whether that ad is displayed or not.
Incompatible file format
When a request is made for a VAST ad but the video player can't find a compatible file to play, a request will be counted but no impressions. See our file format recommendations ...
If a user leaves the page or they experiences a network connection issue after a request has come through, a request will be counted but the impression will not.
Depending on how frequently these events occur, you may see a high number of requests compared to impressions counted.