What is Impression Share?

Impression share is the percentage of auctions for which your ad was eligible and in which it was actually shown. An impression share of 70% means you were not visible in 30% of the relevant auctions: that is missed potential.

There are two main causes. The first is budget: your daily budget runs out before all relevant auctions have been filled. Google reports this as “Search lost IS (budget)”. The second is rank: your Ad Rank is not high enough. This shows up as “Search lost IS (rank)” in Google Ads.

A high impression share shows that you cover the market well for your keywords. Combine it with the CTR and conversion rate for a full picture of campaign performance.

If you lose impressions on budget: raise the daily budget or narrow your targeting. If you lose them on rank: improve your Quality Score, raise your bid or add assets (formerly called ad extensions). Also use negative keywords to focus your budget on the most relevant auctions.

No. An impression share of 70 to 80% with a strong CTR and ROAS is fine. More budget for more impressions does not always deliver a better ROI.

Yes. You can segment it by desktop, mobile and tablet in your Google Ads reports.

How often your ad was shown in the very first position above the organic results, as a percentage of the impressions you were eligible for there. More at developers.google.com/search.