An Ad impression is counted every time an ad is displayed within the app. Ad impressions and clicks are different and should not be confused. In short, Ad impressions tell the advertisers and developers the number of times the ad was viewed by their users but did not interact with it.
Ad impressions generally come in two forms:
Served Impressions: It is counted as the number of times an ad was displayed regardless of whether the user saw it.
Viewable Impressions: It is counted when at least 50% of the ad is visible to the potential user for not less than one second.
Ad impressions are important as it helps marketers to see how many people see their ad through an app. It also allows them to calculate the Cost per millie (CPM) of marketing campaigns. Moreover, it forms the basis for calculating metrics such as Click-through rate (CTR).
These metrics help advertisers analyze the effectiveness of their Ad campaigns.