what is an impression

An impression is a metric used to quantify the number of digital views or engagements of a piece of content, usually an advertisement, digital post, or web page. It is counted each time an ad is fetched from its source, regardless of whether the ad is clicked or not). Impressions are important because they provide a simple representation of how many people are seeing ads within a particular channel. They are used to measure the performance of most types of online marketing campaigns. Impressions can come in two forms: served and viewable. Served impressions are recorded by ad servers, and are counted whether or not the ad itself is fully loaded and in a space viewable to the end-user. Viewable impressions are defined as those that are at least 50% visible to the user for at least one second). It is important to note that counting impressions can often fall in a gray area, such as whether this includes duplicate views, interactions from bots, or if impressions are even an effective way to measure the success of a digital marketing campaign.