Ad Viewability

Definition:
Ad viewability measures whether an ad had the opportunity to be seen by a user, based on defined visibility standards.

Why it matters:
Ads that aren’t viewable (e.g., served below the fold or for less than a second) provide no value, even though advertisers still pay.

Standard (per MRC):

• Display: ≥ 50% in view for ≥ 1 second

• Video: ≥ 50% in view for ≥ 2 seconds

Best practices:

• Prioritize placements with high viewability rates

• Use viewability metrics in optimization

• Avoid sites with hidden or stacked ads