How to Use Impression and Click Share Metrics to Scale Your Google Ads Campaigns

Any Google Ads pay-per-click (PPC) expert understands that a needed skill of their job is the ability to confidently answer the question “is my campaign performing strongly”? Typical indicators that help answer this include conversion rates, return on ad spend (ROAS), or any number of key events. 

And while these metrics are all great, they only describe what was achieved – not what could have been achieved. Searches for your products or services obviously aren’t infinite things. But what does the ceiling for a given campaign potentially look like? Identifying this accurately can help you understand the scalability of your best performing keywords.

This blog will detail two commonly overlooked yet incredibly powerful metrics that can bridge this knowledge gap: impression share and click share. 

In this article, we will: 

• Clearly define these metrics.
• Cover some common use cases to help you tweak your campaigns.
• Describe how changes in your initial conditions can impact your analysis.

What Are Impression Share and Click Share Metrics?

Google defines click share as “the estimated share of all achievable clicks that you may have received”.

Impression share is basically the same thing but instead focused on how many views your campaigns achieved compared to how many views they could have achieved.  

These metrics offer helpful clues regarding what else you could capture if you were willing to increase your investments for a given theme or campaign. They can be incredibly powerful in establishing budgets and in forecasting potential performance outcomes – especially for those of us amidst 2025 budget planning season!

It’s important to note however that these metrics only account for current conditions (we’ll dive more into this in a bit). They are also only available for Search, Shopping, Performance Max, and Hotel campaign types. 

Simple enough, right? Next, let’s explore how we can use them to plan and optimize campaigns.

Using Impression and Click Share to Improve Campaign Performance

Forecast Growth Potential of Top-Performing Campaigns

Consider the following scenario: 

• Overall campaign budget = $10,000 / month, and we’re currently falling behind our monthly goal. We know we need to increase our spending pace, but we are unsure which of our campaigns should be prioritized.
  • The primary goal is to drive form submissions from a “Contact Us” page (our
    “conversion”).
    • Target cost per conversion (CPA) = $150.
  • Campaign A achieved 7 conversions at a $128 CPA in the past two months. 
  • Campaign B achieved 9 conversions at a $330 CPA during that same timeframe.  

Intuitively, many of us would want to optimize the campaign mix here to favor Campaign A over Campaign B, strictly due to how much stronger it performs from a CPA perspective. 

But…is it even possible to spend more? That’s where click share comes into play. 

Notice that Campaign A’s click share is already at roughly 82%, while Campaign B’s is <20%?

So, while Campaign A might be an attractive choice based on CPA alone, our click share indicates we have very little to grow. The well may not be entirely dry just yet, but it’s getting close. 

This isn’t as hyperbolic as it may sound. Commonly, ad accounts that blend branded keywords (let’s assume this is Campaign A) with non-branded keywords (let’s call this Campaign B) achieve similar results to those pictured above. Branded keywords can drive bottom-funnel actions like form submissions, e-commerce purchases, etc., but often drive a very limited number of searches.  

Evaluate Bid Strategy to Balance Scale and Efficiency

Let’s now consider a third campaign (Campaign C), experiencing seemingly contradictory things…

• Campaign C has the strongest CPA in the account (almost 3x stronger than our earlier described $150 CPA target). Cool!
• It’s capable of scaling, as is indicated by a low click share. Great!
• It’s coming nowhere near hitting the spending target we’ve assigned to it. Huh?!

It might be time to check your bids. You might be chasing a CPA that isn’t sustainable at scale.

It can be easy to fixate on achieving lower and lower conversion costs, especially if you’re trying to demonstrate quick wins. But try not to get greedy. If you undershoot it on your bids because you’re trying to guarantee a low CPA, you might be striking out at auction to your competitors. Consequently, your ads won’t show up as often as they could or should, even if the few clicks you are generating typically yield excellent conversion rates. 

If you find yourself in this predicament, you may want to consider walking your bids up – even if that in turn starts to increase your cost per conversion. Cheaper isn’t always better, especially if you’re leaving potential profitability on the table (uncaptured leads, forgone e-commerce purchases, etc.). Inevitably, we all must balance scale with efficiency. Click and impression share, combined with other KPIs in your Databox dashboards, can help you discover if such opportunity is indeed being missed.  

Spot Campaign Flaws with Click and Impression Share Insights

Let’s assume the worst is happening for a moment: your campaign has a low click share, it’s overspending, your CPA is garbage and so is your click-through-rate (CTR).  

But doggonit, you’re not ready to give up on it. Perhaps on some instinctual level you know this campaign is capable of achieving great things. Regrettably, it’s just flailing at the moment.

In this case, it’s not unreasonable to imagine there may be an oversight somewhere in how you’ve set up your campaign.   

This is a good time to audit your targeting settings and/or your ad creatives. Analyze your CTRs at the ad-level, your search terms reports, or even your quality scores to help pinpoint potential trouble areas. Perhaps your keywords don’t match your ad headlines. Maybe you’re accidentally targeting irrelevant geographies. Or perhaps your keywords are just too broad to capture relevant searchers. 

PPC experts are great at many things, but they are still very much human beings. Humans make mistakes. Click share, when combined with other measures like those described above, can help you identify if basic human errors are hindering a campaign’s potential for greatness. 

When Your Conditions Change, Your Analysis Should Change Too

As mentioned previously, click and impression share only describe what you could have achieved under current conditions. But what exactly are “current conditions”? Further, why would changes to them lead to a change in how we should analyze the data? 

You Expanded Your Audience

In simplest terms, the way targeting works in Google Ads is more about defining who you don’t want to see your ads than who you do want to see your ads. Their platform offers a variety of tools to carve their massive global audience down to only the narrowly defined group of users that you actually care about. In essence, each targeting lever you might pull on the backend is similar to a filter you might apply to a spreadsheet database of billions of individual contacts. 

Say you have geographically narrowed your audience – maybe your campaign is focused on a handful of European countries. Expanding your geographic targeting to include North and South America can instantaneously grow the number of people making it past your targeting filters in Google Ads. 

You might see a pattern similar to the following in the months that follow…

Notice how the impression volume starts leaping in June while the impression share decreases? If all things truly remained fixed as they had in May, this wouldn’t make much sense. These seemingly contradictory states indicate something about your targeting has changed – something that expanded your initially defined audience. 

These types of decisions can often be performed on the fly as we chase the latest conversion opportunity. It’s important to keep in mind though that this will likely alter how you should interpret your next click or impression share report. 

Your Competitors Increased or Decreased Ad Spend

Your competitor ad spend, much like your own, is likely not a flat, linear investment. It can go up and down in a given day, month, or even year depending on seasonality or general shifts in business priorities. As competitor ad investment fluctuates, so too will your impression or click shares. If your competitors are spending less, you are likely experiencing a boost in click and impression share. If they are spending more, your shares are likely going down. 

If you’ve ruled out changes you have directly made to your campaign as the culprit for shifts in click or impression share, there’s a good chance it’s related to your competitive landscape. You can confirm this with a quick look at “impression share lost” metrics using Databox’s custom metrics builder. These metrics offer a little more color regarding if and how you are losing ground to competitors at auction. 

Learn how to create custom Google Ads metrics in Databox in this article: Overview: Metric Builder for Google Ads.

Getting Started Monitoring Your Impression and Click Shares

Impression share and click share are two powerful metrics that many PPC managers often tend to neglect. Unlocking their potential can help you forecast and scale top performing campaigns, enhance your understanding of your competitive standing, and help you identify poorer performing ad settings. 

Like any other metric, these metrics should not be assessed in isolation. As you build out your Google Ads Databox dashboards, remember the question you are asking and how these metrics, if paired with others available (CTR, CPA, ad spend, conversion volume, etc.) can help answer them. Make sure you are also thinking critically about how changes to your initial targeting conditions or the competitive landscape can alter the results of your estimates and forecasts.