Measurement

Viewability — Definition & Explanation

The measurement of whether an ad had the opportunity to be seen by a user. The MRC/IAB standard requires 50% of the ad's pixels to be in the viewport for at least 1 continuous second (2 seconds for video). Industry average is ~55%; premium publishers achieve 70%+.

How Viewability Works

Viewability is measured by JavaScript tracking code that monitors the ad container's position within the viewport. Measurement vendors (IAS, DoubleVerify) provide accredited viewability measurement across publishers.

Why Viewability Matters for Publishers

Higher viewability directly increases CPMs. Advertisers pay 30-80% more for impressions above 70% viewability. Stellor Media's implementation guidance helps publishers maximize viewability across all placements.

Frequently Asked Questions

What viewability rate do advertisers require?

Most programmatic campaigns target 70%+ viewability for premium placements. Campaigns below 50% viewability may be excluded by brand-safe buyers.

How can publishers improve viewability?

Implement lazy loading for below-fold units, use sticky ad formats, optimize page layout to keep ads in-view during content consumption, and avoid excessive page length.

Does Stellor Media help publishers improve viewability?

Yes. Stellor's publisher success team reviews ad placement and provides actionable recommendations to improve viewability across all formats.

Related Terms

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