Definition
Impression share lost (rank) is the share of impressions you missed due to insufficient ad rank (bid and quality).
How to use it
- Improve rank via relevance, landing page, and creative quality, not only bids.
- Use break-even CPC/CPA constraints to avoid bidding into unprofitable territory.
Measured as
Measure Impression Share Lost (Rank) with a fixed attribution window, conversion event, and spend basis before comparing campaigns or creative tests.
Operator takeaway
- Improve rank via relevance, landing page, and creative quality, not only bids.
- Use break-even CPC/CPA constraints to avoid bidding into unprofitable territory.
- Use Impression Share Lost (Rank) only inside a stable attribution rule, conversion definition, and time window so campaign comparisons stay honest.
- If performance changes, check whether the metric moved for a real business reason or because the measurement setup changed underneath you.
Next decision
- Read Max CPC and break-even CPC: how to set bidding targets from margin if the decision depends on interpretation, policy, or trade-offs beyond the raw formula.
- Decide which report owns Impression Share Lost (Rank) before comparing campaigns, channels, or creative tests.
Where to use this on MetricKit
Guides
- Max CPC and break-even CPC: how to set bidding targets from margin: Max CPC formula guide: translate AOV, CVR, and contribution margin into break-even CPC and a target CPC with buffer.
- Creative + landing page playbook: diagnose CTR/CVR, then set break-even targets: A practical playbook for improving paid ads performance: use CTR/CVR diagnosis, set break-even CTR/CVR/CPM targets from your economics, and fix the biggest lever first.