What are impressions in online marketing?

An impression, also known as an ad view, is a key term in online marketing and counts how often an ad or a piece of content is shown to a user on a website or in an app.

Impressions measure the visibility of an advertising campaign or of a piece of content, and they are an important indicator of the reach of a campaign. It is important to understand that impressions are not the same as a user actually interacting with the ad. They only count how often an ad was exposed to users.

Examples of impressions

Impressions can occur in different formats and across a range of platforms. Some examples:

• Display ads on websites: every time a banner or a sidebar ad appears on a website, that counts as one impression.
• Search advertising (SEA): the number of times an ad is shown in the search results of Google or Bing.
• Social media posts and ads: on platforms such as Facebook, Instagram and Twitter, an impression is counted every time a post or an ad appears in the feed of a user.
• Video ads: on platforms such as YouTube, a video ad that appears before or during a video counts as an impression.

When are impressions counted?

Impressions are counted as soon as the ad or the content is shown to the user. There are specific criteria that have to be met before an impression counts as valid, and those criteria can vary by platform and ad format. In general, the following guidelines apply:

• Ad load: the ad has to load successfully on the page or in the app. Ads that load only in part, or that stay invisible because of technical problems, do not count as impressions.
• Viewability: some platforms require a certain percentage of the ad to stay in the visible area of the screen for a certain time before it counts as an impression.
• Repeat views: repeated ad views by the same user can be handled differently depending on the platform and the campaign settings. Some systems identify and count repeated views separately.

(Source: Google Ads Help: impressions explained → https://support.google.com/google-ads/answer/6320?hl=en)