Impression Share Is Coming—What Now?

August 30, 2019

Starting in October, Google will no longer be offering average position as a metric. Read on to learn more about transitioning to the new impression share and impression rate metrics and what Marin can do to help.

So...What Are Impression Share and Impression Rate?


By definition, impression share is the percentage of impressions that your ads receive compared to the total number that your ads are eligible to get in the top five ad positions on the search engine results page (SERP). Impression share is a great way to find out how much more you can be doing—it shows you any missed opportunities by indicating how often a particular ad showed up in the top search results.

Average position didn’t accurately measure if ads were showing up above the organic results or not, only the order versus other ads. This left advertisers guessing.

Impression % (or rate) shows you how often your ads are showing at the top of the SERP. In other words, for each of the top five ad positions, you can see the percentage of appearances that your ad is making. This addresses another shortcoming of average position, as even an ad in position 2 might be at the bottom of the page.

Impression share metrics

The three versions of impression share all measure your impressions divided by the total eligible impressions for your ads, based on different locations on the SERP:

  • Search absolute top IS: The impressions you’ve received in the absolute top location (the very first ad above the organic search results) divided by the estimated number of impressions you were eligible to receive in the top location. This is a new metric.
  • Search top IS: The impressions you’ve received in the top location (anywhere above the organic search results) compared to the estimated number of impressions you were eligible to receive in the top location (also a new metric).
  • Search impression share: This is an existing metric that measures impressions anywhere on the page.


Impression rate metrics

These two metrics are only based on your impressions, not the total number of eligible impressions.

  • Impr. (absolute top) %: The percent of your ad impressions that are shown as the very first ad above the organic search results.
  • Impr. (top) %: The percent of your ad impressions that are shown anywhere above the organic search results.


A quick way to remember the difference between impression share and impression rate: impression share is the percentage of total possible impressions in the top five SERP slots; impression rate is the percentage of impressions for each of these five slots.

How Do I Optimize for Awareness?


Advertisers who are more focused on driving awareness than ROI can focus on impression share or impression % (rate).

We recommend advertisers be careful with Google’s new impression share options in Smart Bidding. The impression share data isn’t available the same day, so it’s hard to monitor performance—setting a high target may significantly increase your spend by making you eligible for additional, unwanted auctions.

What Metric Should I Target?


The easiest way to set your targets is to use your recent performance for campaigns across the impression % (rate) metrics and use this as a starting point. This will ensure the smoothest transition from targeting a position to targeting impression share.

The table below shows our default mapping from a position target to impression %. This should only be used for advertisers with limited historical data.

impression share



How do you make the switch from average position to impression share?

Marin’s Awareness Targeting


Marin now offers a bid strategy known as Awareness Targeting, which targets impression rate instead of target position for Google campaigns. Think of this as automatically setting bids to achieve your awareness goals.

For existing Marin advertisers, impression rate targets for Google are automatically set based on recent performance. All current customers can login to MarinOne to view their new awareness targets.

The benefits of Awareness Targeting include:

  • Goals-by-device: Marin optimizes devices independently because user behavior varies a lot between desktop and mobile.
  • A responsive intraday bidding engine: By running every four hours using the latest prominence signals, Awareness Targeting ensures that advertisers are hitting their targets and maximizing reach, especially on high volume, highly competitive terms. This is a great way to stay ahead of competitors.
  • A holistic account strategy: You can apply bid strategies across multiple Google accounts within the same workflow, instead of individually.
  • A single bid strategy: One that’s compatible with position-based bidding for non-Google publishers and impression share metrics for Google.
  • Immediate setup and launch: Advertisers can dive right in and begin targeting to impression share. No historical data needed!


impression share


Maximize Your Search Reach


Google has been making changes to depreciate the value of ad position metrics for quite some time, and has been encouraging advertisers to focus on targeting impression share. Now that Awareness Targeting is readily available in Marin, it’s easy for our advertisers to drive campaign goals that maximize the reach on the search results page.

Want to learn more? Schedule a demo, or if you’re a current customer, reach out to your dedicated account representative today!

Farah Shalwani

Marin Software
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