Definition
Impression
A single instance of a notification, ad, or piece of content being displayed to a user. Used to calculate view-based metrics like CTR and conversion rate.
What does Impression mean?
An impression is a single recorded instance of content, such as an ad, notification, or CTA, being rendered and shown to a visitor, whether or not the visitor engages with it further. It is the base unit that view-dependent metrics are built on.
Why does Impression matter?
Impressions matter because they establish the denominator for rate-based metrics like click-through rate and conversion rate, and without accurate impression counting, teams cannot tell whether a low number of clicks reflects a genuinely unappealing element or simply very few people ever saw it.
How is Impression applied in practice?
Impressions are counted automatically by analytics and advertising platforms whenever content loads within a visitor's viewport, and teams often distinguish between raw impressions and viewable impressions, the latter requiring the content to actually be visible on screen rather than merely present in the page's code.
Related terms
Where this fits
Impression sits in the conversion analytics part of the NotiProof resource network.
Read the Conversion Analytics guide