Unlock the Hidden Profit in Your Adwords Account - Understanding Impression Share

Today we're going to talk about a very important, but often under-used, metric in Adwords: Impression Share. This metric is one of the "hidden" columns in Adwords, meaning that by default you won't even see this metric. You need to "unhide" it by selecting it from the list of hidden columns in Adwords. Which is a shame because understanding what this metric means, how to view it, and how to make decisions based on it could unlock thousands of dollars' worth of hidden profit in your Adwords account.

If you are currently running your own Ecommerce Adwords account and you do not have a solid understanding of this metric, then read on, because you could be missing out on a tonne of profit that is easily achievable with a minimal amount of work. All it takes is some increased understanding.

What is Impression Share?

In other advertising channels such as banner ads, TV or Radio, you may have heard of a term called "Share of Voice" (SOV) and you may have a vague idea of what this means. Put simply, it is your share or portion of the available ad views. A 50% SOV would indicate that of all the ad views or impressions available on that channel, your ads showed up on half of them.

Search Impression Share (IS) is basically the same thing, but for paid Search marketing. According to Google, impression share is defined as:

Impression share (IS) is the percentage of impressions that your ads receive compared to the total number of impressions that your ads could get.

Impression share = impressions / total eligible impressions

It's important to note that your impression share is calculated based on your eligible impressions. Google gets A LOT of searches every day, and you are only going to be eligible to show on some of those impressions. What you are eligible to show on is determined by your targeting settings such as your keywords, location targeting, time of day bid adjustments, device settings, and more.

What's a "Good" Impression Share?

When it comes to IS, generally higher numbers are better. But, you are rarely going to show up ALL of the time. 100% Impression Shares are rare. So, what constitutes a "good" number for your Impression Share?

Well, this bit is subjective and dependent on a lot of factors like your industry, conversion rates, budgets, etc. But for a VERY broad starting point, I'd recommend considering 70%. If your overall account Impression Share is in excess of 70%, you are getting a healthy share of your market. A lot less than this, and you may have room available for expansion, assuming you have the budget and performance levels to do so. More on that below!

How to View Your Impression Share

As I mentioned above, Google does not make it immediately obvious what your Impression Share actually is. The default settings on Adwords seem to cater for the masses, and the masses are not very well-educated or knowledgable when it comes to Adwords. Most people don't understand what IS is and thus having the column showing up by default might confuse a lot of more basic advertisers, so they don't show it right away. After reading this article though, you will no longer be part of said masses and hopefully you'll start having the IS column showing up in Adwords most of the time.

To enable your IS column view, first click here in Adwords:

enablind impression shares column in adwords.png

After you've done this you it will open up a box where you can choose what columns you want to pull up. Under the "Competitive Metrics" section, select these three columns:

saving impression share column sets adwords.png

You can see at the bottom there I ticked the box to save this as a column set and I called it "IS" for Impression Shares. I recommend you do this, it'll make the columns much quicker to pull up in future. Also note that I added three columns, not just the "Search Impression Share" but also the "Search Lost IS (rank)" and the "Search Lost (budget)". You should add these columns too as they give you an important part of the overall picture. Don't worry, I'll explain what they mean and how you use them below.

Reasons for Losing Impression Share - Rank and Budget

Most of the time, your IS is not going to be 100%, meaning that almost all the time you will be losing out on some of your eligible impressions for one reason or another. Don't sweat it, 100% IS is rare, and for the majority of times where your IS is not hitting the full 100% there are two main reasons for this: rank and budget.

Losing Impressions due to Rank

This is illustrated by the column "Lost IS (rank)". What this metric means is, "of the impression share you are losing, what percentage of it is due to low ad rank?" Ad rank is determined by a number of factors, but the primary factor (and the factor that you can influence the quickest) is your CPC bid. For the purpose of this article then, I'll consider your CPC bid as the only factor affecting your "Lost IS (rank)" column. There are other factors that affect it, but those are much slower to improve and are deserving of articles of their own. So, then, what we are left with is that if you are losing impression share due to rank, that means to improve impression share you need to increase your bids.

Losing Impression due to Budget

The other main reason you could be losing impression share is due to having too low a budget on your campaigns. This is shown by the column "Lost IS (budget)". If you see a high number here, that means you could have shown a lot more ads, but because the budget cap you set on your campaign is too low, you are missing out on a bunch of potential impressions.

Understanding your Account Performance

In PPC land when we discuss an account's "performance" what we are usually referring to is its primary Key Performance Indicator (KPI) that dictates whether the account is profitable or not. In the case of Ecommerce Adwords, we're usually talking about Revenue Over Ad Spend (ROAS). In Google-speak, this is called "Conv. value / cost". This metric looks at the total revenue achieved by your ads and divides it by the total ad spend to give you a ratio of the two numbers.

When analysing your IS, it's also important to know and understand your account performance, i.e. ROAS, as this determines whether or not you are in a position to be able to improve your IS. If your IS is really low and you want to improve it, to improve it you are going to need to spend more by either increasing your budgets, bids, or both. You can only logically increase your spend, then, if your account is performing profitably enough for you to spend more while still making a profit. So, when doing an IS analysis on your account, make sure to also have your "Conv. value / cost" column active and make sure you know what is the minimum profitable ROAS for you.

Making Decisions - the IS Decision Grid

I'll explain each of these situations in detail below, but to start us off let's look at a very simple IS decision grid which will help you understand how to move forward:

the impression share decision grid.png

What we have here are a few different scenarios, here's how they break down:

1. ROAS is Above Target

Let's say your Costs of Goods Sold (COGS) are around 50% of your revenue. That would mean for you to just break even on your ad spend, you'd need to get twice as much revenue as you spend on ads, i.e. you need a ROAS of 200%. In this scenario, you might decide to set your target ROAS at 300%. At 300% ROAS or above, you are generating plenty of revenue, enough to cover your ad spend and COGS, and then some. So if your ROAS is even higher than 300% in this case, let's say it was as high as 600%, that'd mean you'd have room to let your ROAS decrease and still be making a tidy profit.

That's why, if your ROAS is above target and you are losing impression share due to rank (i.e. low bids), you should increase your bids. Increasing your overall CPC bids will indeed increase your costs, and increasing your costs will make your ROAS go down. But, in this case, your ROAS can afford to go down and still be profitable, and increasing your bids will increase your IS which will lead to more clicks and sales. End result: more profit for you.

If your ROAS is above target and you are losing IS due to budget, then you should increase your budgets. In this case, every dollar you spend on ads is generating more than that in profit for you, so why would you want your campaign to be artificially limited by budget? Barring issues with fulfilment, you probably wouldn't, so go ahead and raise your budgets ASAP!

2. ROAS is on Target 

If your ROAS is bang on target and you are losing impression share due to rank, then there's not much you can read in to this. In this case, you wouldn't want to make any bid changes as a consequence of your Lost IS due to rank. You might still want to make bid changes, and you probably should, but what I am saying is that Lost IS due to rank should not be one of the deciding factors in what bid changes you make. Make your bid changes based on other criteria such as performance at the keyword or ad group level. Do not go and increase or decrease bids because you wanted to change your Lost IS due to rank.

Now, if ROAS is bang on target and you are losing a bunch of IS due to budget, then you DO want to make a change. In this case, it's the same scenario I described in the last section: your account is profitable and every $1 you spend on ads is generating profit for you. If $1 spend on ads is generating, say, $3 of profit for you, you would not want to have a budget cap on your campaigns. You'd want to spend as much as possible. Upping your budget is not going to directly affect your ROAS, it's going to increase your volume at the same ROAS (assuming all else is equal), so go ahead and crank those budgets up.

3. ROAS is not profitable

When your ROAS is way below target, then you are in a situation where spending a dollar on ads is not generating enough dollars for you to profit. Your Adwords account is essentially a cost to you at this point, and you thus have much bigger issues to fix first before you can even begin to do an IS analysis.

If you are in this spot, then go and focus on getting profitable. Stop reading this article, it's not going to tell you how to fix your issue (although browsing around some of the articles here on our blog might!). You might have an issue with your bids, ad creative, channel selection, targeting, or overall strategy. Whatever is the issue is outside the scope of this article. Fix it first then come back here.


And there you have it: a sub-10 minute read that might help you make thousands more dollars of profit in your Adwords account right away. For those of you reading this that are not in one of those sweet green spots in my above IS decision grid, then OK this article did not make you anymore money... yet. But hopefully you did learn something and will now know to check these metrics on a regular basis. You may not be losing any IS now, but this changes on a regular basis and the metrics should be checked at least once a week, ideally.

If you are one of the lucky sods who were in the green part of the decision grid when they read this article, then congrats! We just unlocked a bunch of profit that was sitting dormant in your Adwords account :)