Marketing Glossary

Ad Impression Share (Eligible Impressions Won)

The percentage of the impressions you were eligible for that your ads actually won — a direct read on how much visibility budget or rank is costing you.

Used in context
3.11 — Competitive Visibility Audit

…Your current ad impression share shows meaningful headroom to capture more visibility without changing targeting.…

What it means

Ad Impression Share is the percentage of total impressions your ads received compared to the total estimated impressions you were eligible to get, based on targeting settings, budget, and Quality Score.

A low impression share usually points to one of two causes — budget limits capping how often your ads can show, or rank limits from low bids or Quality Score — and each requires a different fix.

Reveals hidden opportunity

It shows exactly how much eligible visibility is being missed, not just what’s being won.

Diagnoses the root cause

Splitting share loss by budget versus rank tells you precisely what lever to pull.

Guides scaling decisions

High impression share with strong ROAS is a clear signal it’s time to raise budget.

DNA’s Take

DNA's Take: We check impression share before recommending any budget increase — it tells us whether more spend will actually buy more visibility or just get absorbed by the same capped auction.

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