What Is Impression Share, and Why Does It Matter?

Global spending on digital ads is expected to overtake television in total ad spending this year. That's a first for digital ads. So that means it's reckoning time for many marketers to truly understand their online advertising campaigns. To do this requires knowledge of an ad's impression share. In online advertising, an "impression" is made each time an ad is shown on a search results page, or from a display ad. Impressions are counted against an advertiser's account once that ad loads and appears on the user's screen.

If people aren't served by your search or display ads, there will be no ad clicks, which can affect the impact of your online advertising campaigns. That's what makes the impression share such an important part of online advertising knowledge.

Here, we'll define impression share and discuss the different types that are available to advertisers. We'll learn why impression share is important, and what ideas we can provide to make your campaigns more successful over time.

Making an Impression Count

Impression share is the metric used by advertisers to see how well paid ads in Google AdWords, Bing, or other ad networks are performing with a set of certain keywords. Advertisers can see the percentage of specific ad impressions served up on screens for a set of keywords, compared to the total number of ad impressions that were eligible to serve.

If your keywords were searched 1,000 times in a week by web users, that number (1,000) is your eligible impression count. If your search ad was served on half of those impressions, your ad's impression share would be 50 percent

Why Impression Share Is Important

Ad industry experts see impression share as an important metric that shows advertisers how much more they could do with their current ad campaigns. Most of the other metrics show advertisers current stats on ongoing campaigns, rather than potential opportunities.

Impression share works best after a campaign has gone through its early stages and has already played the field with many keyword variations. Once you see which keywords are resonating, then it's time to track your impression share to achieve higher scale.

Different Types of Impression Shares

There are different types of impression shares that AdWords offers. Here's a brief synopsis:

  • Exact Match Search Impression Share

Exact match impression share is the percentage of impressions ads on exact keyword searches. When advertisers run specific keywords, this type of impression share shows them how often ads show for these exact matches.

  • Search Impression Share/Display Impression Share

You can also use impression share in ads on Google's search network and/or display network. A single impression occurs when your ad is served up in display form or on a search results page.

  • Budget Search Lost Impression Share/Budget Display Lost Impression Share

If your ad budget is constrained, AdWords will show you a "lost" impression share to let you see the percentage of ads not served as a result of the low budget. This can run on both search results ads and display ads.

  • Rank Search Lost Impression Share/Rank Display Lost Impression Share

Similar to lost impressions due to low budgets, this category of impression share shows what advertisers are losing as a result of the low rank of their keywords. Google calculates ad rankings this way: Quality Score x Max CPC Bid =Ad Rank

More Tips for Impression Shares

Advertisers can improve their impression shares with different tricks. One idea is to adjust your ad's geotargeting. This involves adjusting your ad to fit a specific market or language. By customizing ads for niche markets, advertisers can take advantage of impression share across different zip codes, cities, states, and regions anywhere.

Another tip to improve impression share is to focus on your pay-per-click ad quality. Maybe you can shape the ads more closely to your product or service's unique selling proposition, or look to achieve more clicks from a better call-to-action in your ads.

Impression share is an important part of the digital advertising mix, and you'll see better results when you master this part of the equation.