Top Impression Share measures impressions received among top ads against the estimated opportunities for which the ad was eligible to appear there.
Example of Top Impression Share
Suppose an ad receives 300 top impressions from an estimated 600 eligible top-impression opportunities. Its top impression share is 50%. Dividing those 300 impressions by all impressions the ad received would answer a different question about placement rate.
Why Top Impression Share matters
It matters because paid search can spend budget quickly. Knowing this term helps teams control intent, targeting, bidding, creative, conversion tracking, and lead quality instead of optimizing for surface-level clicks.
Related terms
- Absolute Top Impression Share
- Impression Share
- Conversion Tracking
- Target ROAS
- Enhanced Conversions
- Target CPA
Practical distinction
The denominator is eligible opportunities, not all impressions received. Share measures coverage of an opportunity; placement rate describes where received impressions appeared.
Source notes
Frequently Asked Question
What does Top Impression Share mean?
Top Impression Share measures impressions received among top ads against the estimated opportunities for which the ad was eligible to appear there. Formula: Top impressions ÷ estimated eligible top impressions × 100.