What Is Impression Share?
Also written as IS, search impression share, lost impression share.
Definition
Impression share is the percentage of impressions your ads got out of the total they could have got. Google works it out as impressions divided by total eligible impressions. If a store's candle ads showed on 40 of 100 chances, its impression share is 40 percent.
Written by Christopher Krassnig, Founder & CEO of ZenoX Media. Written by the ZenoX team from the accounts we run. Definitions are general; the numbers in examples are maths, not client results.
Impression Share, Explained
Impression share answers one question: how much of the available traffic did you actually take? Total eligible impressions is an estimate from Google, based on things like your targeting, approvals and quality. So treat it as a guide, not an exact count.
Two related columns tell you why you missed out. Search lost IS (budget) is how often your ads did not show on the Search Network because the budget was too low. Search lost IS (rank) is how often they did not show because of poor Ad Rank.
The two call for different moves. Lost to budget can mean more budget would buy more shows, if the campaign is profitable. Lost to rank points at bids, ad quality and the landing page.
A low number is not a problem on its own. Winning every impression is rarely the goal, because the last few can be the most expensive. Google itself warns against relying on Lost IS (budget) with Maximize Conversions, since that column ignores how the strategy handles budget.
The one place to push for high share is your own brand name.
How We Use It at ZenoX
We read impression share as context and never as a target on its own. Brand Search should sit high. On feed campaigns, a low share only matters if the campaign makes money at the current spend. Otherwise more impressions just buy more loss.
Questions People Ask About Impression Share
How Is Impression Share Calculated?
Google divides your impressions by the total eligible impressions. Total eligible is an estimate of how often your ads could have shown, based on targeting, approval status and quality. So 500 impressions out of an estimated 1,000 is 50 percent.
What Is a Lost Impression Share?
It is the share of shows you missed. Search lost IS (budget) means your budget was too low. Search lost IS (rank) means your Ad Rank was too low. The first points to budget. The second points to bids, ad quality or your page.
Related terms
- ImpressionAn impression is counted each time your ad appears on Google or the Google Network.
- Auction InsightsAuction Insights is a Google Ads report that compares your results with other advertisers in the same auctions.
- Ad RankAd Rank is the score Google uses to decide if your ad can show and in what order among other ads.
- Limited by BudgetLimited by budget means your daily cap stopped Google from spending more on traffic it judged worth buying.
- Brand Search CampaignA brand search campaign is a Search campaign that only bids on your shop's own name and close spellings.
Go deeper
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