Impression share lost to rank
also called Rank-lost impression shareLost IS (rank)
Definition
The share of available auction impressions you did not receive specifically because your ad rank was too low.
Scope, grain and dimensions
- Grain
- One number per segment and date range, or one row per keyword or campaign.
- Dimensions
- keyword · campaign_name
- Required filters
- segment_id · date_range
- Aggregation
- An unweighted average across keyword-day rows.
- Metric type
- share · share of available auction impressions (stored 0 to 1, shown as a percent)
Data sources
Where you'll see this
Named reports that normally include this metric.
Paid search performance report
Skills and analyses that use it
Skills carry the judgment; the analysis verbs do the reading.
Analysis verbs
paid_impression_share
Method rungs and levers
A rung tells you what a movement here can and cannot explain, read the rungs below it first.
levers L8 Paid/organic interplay
Ask Quattr
- "Where are we losing impression share to rank?" Simulate this →
- "Which keywords have fixable auction ground?" Simulate this →
Caveats, freshness and failure modes
The semantic layer averages Google Ads' own per-row rank-lost impression share; nothing is recomputed here.
This is rank-lost only. Impression share lost to BUDGET is not measured anywhere in the product: the budget-lost measures exist in the semantic layer only on a campaign-grain dataset that no tool reads, and the keyword-grain dataset this tool uses has none. A rank-lost figure therefore does not account for the impressions a capped budget cost you.
The tool's own response key drops the rank qualifier, so a consumer reading the raw payload cannot tell which loss reason it has. Always carry the qualifier in the sentence.
Won share and rank-lost share do not sum to one, budget loss and ineligibility live outside both.
Always per segment; unweighted average across rows; stored as a fraction between 0 and 1.
- Freshness
- ~1 day behind, Ads reporting settles overnight; same-day spend is provisional.
Common failure modes
- Reading a rank-lost number as total lost impression share and concluding the budget is fine.
- Adding won share and rank-lost share and expecting 100%.
- Reading a rise in rank-lost share as an improvement because a direction oracle painted it green.
Not the same as
The confusions that cause the most wrong decisions.
Impression share lost to rank Search impression share Compare definitions →
One is what you won; this is one named reason for part of what you lost. They are separate averaged columns and do not complement each other.
Watch this metric read in a real run
All runs →
Related metrics and workflows
Verification
A definition is the smallest part of this.
The measurement matters because something acts on it. Here is the rest of the showcase, in the order most people find useful.