What is impression share?
Malthe Weibeck Thomsen · Growth Hacker · Senior Pull Specialist · 8 July 2026 · 3 min.
Definition
Impression share is the number of impressions your ads received, divided by the estimated number of impressions they were eligible to get.
Also called: Impression Share, IS
Sådan virker det
Impression share er den andel af de mulige visninger, du faktisk fik. 62 % betyder, at du gik glip af 38 % — enten fordi budgettet slap op (lost IS budget) eller fordi Ad Rank var for lav (lost IS rank). Det viser, hvor meget vækst der stadig ligger på bordet.
01What you're missing — and why
An impression share of 62% means you missed 38% of the possible impressions. Google even tells you why: “lost IS (budget)” means budget ran out, while “lost IS (rank)” means your Ad Rank was too low. That makes impression share a concrete growth map — it shows precisely what's holding you back.
If the loss is driven by budget, there's likely profitable demand you're not capturing. If it's driven by rank, the path lies in higher relevance (Quality Score) or bid. Without impression share, you don't know whether the ceiling is self-imposed or forced.
Frequently asked questions
What do lost impression share (budget) vs (rank) mean?+
Lost IS (budget) means you missed impressions because budget ran out — often a sign of unmet, profitable demand. Lost IS (rank) means your Ad Rank was too low, which you raise with better relevance or a higher bid.
Should I always chase 100% impression share?+
No. On generic searches, 100% is rarely profitable. Impression share is a diagnostic tool — it shows where there's growth to capture, not a goal in itself. Weigh it against break-even and profit.
Related terms
Glossary
What is Ad Rank?
Ad Rank is the value that determines your ad's position in Google's search auction. It's calculated roughly as your bid times your Quality Score, plus the expected impact of ad extensions and context.
Read the entry →Glossary
What is Quality Score?
Quality Score is a rating from 1 to 10 that Google assigns your keywords based on three factors: expected click-through rate, ad relevance and landing page experience.
Read the entry →Glossary
What are brand vs generic searches?
Brand searches are searches that contain your name (people who already know you). Generic (non-brand) searches are category and product searches from people who haven't yet chosen you.
Read the entry →
Malthe Weibeck Thomsen
Growth Hacker · Senior Pull Specialist at Oaksmond
Pull specialist with 8+ years' experience. Comes from the agency world and has since worked as an independent consultant for several of the country's largest brands.
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