Impressions

Category: Metrics

The number of times a piece of content or ad was displayed.

Impressions differ across platforms — a viewable impression (50% of pixels in view for 1 second) is a stricter definition than a served impression. Impressions are top-of-funnel; use them to measure reach and awareness. Never optimize toward impressions alone — CPM buys can chase cheap, low-quality inventory.

See also: reach, cpm, viewability