what is an impression in advertising

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. Impressions are not a measure of whether an advertisement has been clicked on, but how many times it was displayed or had potential "eyeballs" on it. Impressions are important to mobile marketing because a popular method of purchasing advertising is by the number of impressions an advertisement generates. Advertising formats tend to charge per thousand impressions, so it’s essential for advertisers to know how many impressions a CPM advert generates to understand campaign cost. Impressions are important because they provide a simple representation of how many people are seeing ads within a particular channel. Calculating the number of impressions a campaign generates is also one of the simplest ways to ascertain how far an advertising channel really reaches. Knowing how many impressions an advertising campaign generates helps marketers generate a number of other marketing metrics too, such as Click-Through Rates (known as CTR) . An impression is counted each time an ad is shown on a search result page or other site on the Google Network. Impression tracking is a common metric for measuring the performance of most types of online marketing campaigns. Impression tracking has a 24-hour attribution window, which means that a user who sees an ad for an app must install it within that period to be attributed to that impression. App developers get paid for every 1,000 ad impressions, which is measured by eCPM.