An ad impression is a metric used in digital advertising to count the number of times an advertisement is displayed, regardless of whether it was clicked or not. Each time an ad is shown on a user’s screen, it is counted as one impression. This metric is commonly used to gauge the reach and frequency of an ad campaign.
For example, if an ad appears on 100 web pages and each page is visited by 10 people, that ad would receive 1,000 impressions. It’s important to note that impressions don’t measure engagement or effectiveness of the ad, but rather the exposure and visibility it gets in front of an audience.