Impression share

Example

A roof repair campaign shows 30% impression share, 45% lost to budget and 25% lost to rank. The direction is clear: most of what is missed is a budget problem.

With 3,000 impressions a month, the eligible total is 3,000 ÷ 0.30 = 10,000. Covering half of what budget loses brings impressions to about 5,250. At a 6% clickthrough rate that is roughly 315 clicks instead of 180, and at a 5% conversion rate about 16 enquiries instead of 9.

Why it matters for a business

Impression share turns “it is going well” into “how much is left”. A campaign with a good cost per enquiry and a 30% share means two thirds of the demand goes elsewhere, and that weighs more than another rewrite of the ad text.

The two kinds of loss call for different answers. Share lost to budget is solved with money or with tighter targeting. Share lost to rank is a question of bids, Quality Score and relevance — work on the keywords and on the page.

The metric has limits. Google reports it for some campaign types only, and the extremes come back as ranges — “< 10%” and “> 90%” — instead of an exact figure. One hundred percent is rarely the goal either: the last few percent are the dearest to buy. And a high share on the wrong keywords is spend rather than an achievement, so it is read together with clickthrough rate and enquiries.

What to ask

• What is the impression share by campaign and for the keywords that matter most?
• How much is lost to budget and how much to rank?
• What is the share at the very top of the page for brand keywords?
• What would the next ten percent cost, and what would it bring?

Impression share is one of the figures in the monthly report for Google Ads, next to the cost per enquiry.