• by Wes MacLaggan , Columnist, September 23, 2019

On September 30, Google will sunset average position as a metric for search campaigns in hopes of creating a more transparent and accurate form of measurement for marketers. The change was originally announced in February of 2019, and will force advertisers to transition to new impression share and impression rate metrics.

Google is undoubtedly shaking things up for advertisers with this rollout, but there are ways to prepare for the emergence of the new metrics this month.

Start with the Basics

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 for 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 whether ads were showing up above the organic results or not, only the order versus other ads. This left advertisers guessing.

Impression percentage (or rate) shows you how often your ads are showing at the top of the SERP based on your total impressions. In other words, what percentage of the time is your ad in the top spot (Absolute Top) or above the organic results (Top). This addresses another shortcoming of average position, as even an ad in position 2 might be at the bottom of the page.

Measuring Impression Share

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.

Measuring Impression Rate

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

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

How to Optimize for Awareness

For advertisers who are more focused on driving awareness than ROI, impression share and impression rate ensure the ads are meeting a visibility threshold and help raise awareness of the brand.

We recommend that advertisers should 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.

A better approach is to bid to impression rate. This will allow you to optimize for your impression showing at the top of the SERP.

Preparing for the Change

Google has been encouraging advertisers to focus on the impression metrics for quite some time. Many advertisers will feel the impact of the shift to these metrics, particularly because of the new challenges it will present for bidding strategies — in their ongoing quest to drive campaign goals that maximize the reach on the search results page, advertisers will need to set the right bids to achieve their share goal.

Making the switch to the new metrics is mandatory, so advertisers should check any scripts or rules that rely on average position, and update reports and saved columns that include average position.

Google will be automatically migrating “Target Position on Page” Bid Strategies, but has not provided a timeline or details on the migration.

We recommend keeping a close eye on any campaign targeting average position in October to ensure you are getting the results you expect.