The proportion of eligible advertising impressions that your ads received, as estimated by the advertising platform.
A practical example
A search campaign may lose eligible impressions because of its budget or ad rank.
What to watch for
Eligibility depends on targeting and auction conditions. Impression share is not the percentage of all searches in your market.
Related reading
Explore Quality Score and Pay Per Click (PPC). Try our break-even ROAS calculator for a practical next step. See how this fits into Paid advertising.