What is an ad impression?
An ad impression is recorded each time an ad is displayed on a user’s screen. Whether the user notices the ad or not, if the ad is visible on their screens, this counts as an impression.
It’s important to note that ad impressions are different from ad clicks. When an ad impression occurs, it may or may not result in the user clicking on the ad.
By keeping track of this metric, app marketers find out how many users have been exposed to their ads. For developers, ad impressions are important for revenue generation. Measured by a metric called eCPM, app developers get paid for every 1000 impressions within their app.