Viewability: ad viewability

Viewability tells you whether an ad was actually seen (MRC baseline: pixels on screen and time in view).

Impression → viewport → viewability: media context, measurement rules, and reporting practice.

An encyclopedia of digital marketing terms. See also all articles in «Marketer's terminology».

What it is

It matters for display and programmatic; low viewability means paying for hollow impressions.

Protects spend from junk placements at the bottom of the page or autoplay off-screen.

Require viewability reporting, site allow-lists, and formats with real visibility (in-feed, sticky).

Table 1. Definition and business context

Criterion	In short
Definition	It matters for display and programmatic; low viewability means paying for hollow impressions.
Why businesses care	Protects spend from junk placements at the bottom of the page or autoplay off-screen.
Effect when done right	Tightens the link between CPM and actual attention.

Table 2. Practice, ecosystem, and related terms

Area	What to consider
How to apply	Require viewability reporting, site allow-lists, and formats with real visibility (in-feed, sticky).
Works with	Works with programmatic and brand metrics.
In the glossary	Programmatic media buying, CPM and cost per mille, Brandformance, Ad frequency and creative fatigue

Tightens the link between CPM and actual attention.

Works with programmatic and brand metrics.