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User Acquisition

Viewability Rate

Also known asViewabilityViewable Rate

The share of served ad impressions that were actually viewable — by the MRC standard, at least 50% of the ad's pixels in view for at least 1 second (display) or 2 seconds (video).

Key takeaways

  1. 01Viewability rate = viewable impressions ÷ measured impressions. A served impression is not necessarily a seen one.
  2. 02MRC standard: ≥50% of pixels in view for ≥1s (display) or ≥2s (video); some buyers require a stricter bar.
  3. 03It is a media-quality metric — low viewability means you paid CPM for impressions nobody saw.
  4. 04Verified by third parties (IAS, DoubleVerify, MOAT); strong placements clear 70%+ viewability.

Viewability rate is the share of served ad impressions that were actually viewable to a user. The distinction matters because a served impression — [[cpm]] is priced per thousand of them — is not the same as a seen one: an ad rendered below the fold, in a background view, or scrolled past instantly was paid for but never had a chance to work.

The industry benchmark is the MRC (Media Rating Council) viewable-impression standard: at least 50% of the ad's pixels in view for at least 1 continuous second for display, or 2 seconds for video. Some buyers demand stricter custom standards (100% of pixels, or longer dwell), so always confirm which definition a viewability figure uses.

Viewability is verified by third-party vendors (Integral Ad Science, DoubleVerify, Oracle MOAT) rather than self-reported by the seller, and sits alongside [[brand-safety]] and ad-fraud checks as part of overall media quality. Strong placements clear 70%+; weak inventory sits well below 50%. For app publishers, [[ad-unit]] placement — ensuring the unit is fully on-screen before an impression counts — is the main lever.

Quick answers

What is a viewable impression?

By the MRC standard, a display ad is viewable when at least 50% of its pixels are in view for at least 1 continuous second; for video it is at least 50% of pixels for at least 2 continuous seconds. Viewability rate is the share of your served impressions that meet this bar.

What is a good viewability rate?

Strong placements clear roughly 70%+; the open-programmatic average often sits in the 50-70% range, and low-quality inventory falls below 50%. Higher is better, but pair it with brand-safety and fraud checks — high viewability on fraudulent traffic is still worthless.

Why does viewability matter?

Because you typically pay per impression (CPM) but only viewable impressions can drive an outcome. A campaign at 40% viewability is effectively paying 2.5× the headline CPM for impressions that actually had a chance to be seen. It is one of the core media-quality metrics buyers optimize.

How do I improve viewability?

On the buy side, target placements and publishers with proven high viewability and use verification vendors. On the publisher side, place ad units where they fully render on-screen, do not count impressions before the unit is visible, and avoid stacking or below-the-fold auto-refresh that inflates served impressions without views.

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