What does Impression Share indicate?

• A. The proportion of eligible impressions your ads received within a target set.
• B. The total number of impressions your ads received.
• C. The average position of your ads in auctions.
• D. The rate of clicks per impression.

Answer: (A)

Impression Share shows the portion of eligible ad opportunities you actually received within your target. It’s calculated as your impressions divided by the number of eligible impressions in the same target set, reflecting how often your ads win the chance to be shown given your bids, budget, and targeting. A high Impression Share means you’re capturing most of the opportunities available; a low one suggests there are eligible impressions you’re not seizing, which could be due to budget limits, bidding, or targeting settings. This metric doesn’t equal total impressions (that’s just Impressions), it doesn’t indicate where your ad appears in the auction (average position), and it doesn’t measure click-through rate (CTR).