impression

Impression

A single instance of an ad or piece of content being loaded on a user's screen. Each time an ad renders, that's one impression — regardless of whether the user notices or engages with it.

When you'd see it: Every digital advertising platform — Google Ads, Meta, LinkedIn, programmatic display, connected TV. Impressions are the top of the paid media measurement funnel: they're the starting population from which clicks, conversions, and customers are drawn. The denominator in CTR (clicks ÷ impressions) and the unit in CPM pricing ($X per 1,000 impressions).

Why it matters: Impressions measure reach — how many times your message has had the opportunity to land. High impressions with low CTR signals a creative or targeting problem. Very low impressions on a budget campaign means you haven't bought enough reach to learn anything useful from the data. Impressions are the prerequisite for everything else in paid media.

Common mistakes: Conflating impressions with genuine views. On social platforms, an impression means the content was rendered in a feed — it doesn't mean the user stopped scrolling. Viewability rates (the % of impressions where the ad was actually in view for a minimum time, per MRC standards) can be 50-70% of total impressions. Ask for viewable impressions, not just served impressions, when evaluating display campaigns.

Related CPM, CTR, CPC, paid media, retargeting