Impressions per Session is used to limit the amount of impressions per session for a specific placement. E.g. one can limit it to 10 impressions per session. It means that if 10 impressions have already happened — no ads will be shown in this placement until the app is reloaded. Thus, game balance can be regulated.
Impressions per Session Setting
How to limit the amount of impressions for some placement
Written by Tanya Moroz