In today’s installment of our KPI monitoring & diagnosis series, we’ll focus on analyzing changes in impression share lost due to rank and top impression share.
These two metrics are highly related as having a high absolute or top impression share (IS) percentage is directly related to having a high ad rank. As ad rank falls, you often see a drop in your top IS metrics and an increase in lost IS due to rank.
This isn’t always directly correlated. For example, you might experience a slight drop in ad rank and move to the bottom of the page, but you’re still on the page. In this case, you’ll notice a decline in top impression share, but no change in lost IS due to rank.
To understand ad rank and diagnose this metric, we need to first look into what makes up ad rank.
How ad rank is calculated (the simplified version)
Each time someone searches, Google calculates the ad ranks for all eligible advertisers and orders the ad positions accordingly. Your ad rank matters only in relation to the ad ranks of other advertisers. It’s calculated based on three variables:
- Your max CPC: what you’re willing to pay for a click
- Your auction quality score
- Your assets/ad extensions’ impact on CTR for that auction
As these three factors change, your ad rank and ad position do too.
If your ad rank is too low for your ad to be displayed on the page, then you lose that impression due to rank. Google reports this number in the metric Lost search impression share (rank). This is also called Lost IS (rank).
To understand why we’re losing impressions due to ad rank and why this number changes over time, we need to dig into the three variables.
Changes in quality score
Your quality score is always in flux. As your website, ads, and ad group organization change, your quality score changes. If users click on your ads at differing rates, this can also affect your quality score, as CTR is a component of your score.
The easiest way to diagnose changes is to track your quality score over time.
In this case, an advertiser had launched a new product. The campaign organization was good (hence the high ad relevance), but the landing page and CTR needed help. They did some landing page testing and a lot of ad testing, and in the course of a few months, their quality scores went from a 5 to a 10 for these new keywords.
If you see changes to quality score, these often have a direct impact on lost impression share due to rank.
If you want to dig deeper, here are some more quality score resources:
Max CPC changes
What you’re willing to pay for a click is a massive component of ad rank. If you make significant changes to your bids, then you’ll see changes to your lost impression share due to rank. You should also see changes to your top and absolute top impressions and impression shares.
If you are bidding manually, you should have a good idea of significant bid shifts.
However, if you’re using automated bidding, then you might not see these changes as Google Ads or Microsoft Ads is amending bids on your behalf. It’s easy to miss some keywords and suddenly get fewer impressions. Watching your average CPCs over time can help.
If you switch bid methods, this can also affect your lost impression share due to rank since the new system might make substantial bid changes.
Changing targeting methods
You can look at lost search impression share (rank) for all your search campaigns, a single campaign, an ad group, or individual keywords. This metric will probably also change if you change targeting options by:
- Adding keywords
- Pausing keywords
- Adding negative keywords
- Removing negative keywords
- Changing match types
- Adding or excluding audiences
- Adding or changing time of day, demographic, or other settings
Launching several new ad groups can also be a factor in lost impression share (rank) changes.
Assets (ad extensions)
It’s essential to use the recommended number of assets, as these play a pivotal role in ad rank. It’s easy to miss common for a campaign to miss an asset or two (here’s a guide to identifying this). Adding those missing assets can help mitigate impression share loss due to ad rank.
If you add new campaigns, ensure you’re using all of your assets correctly.
Graphing top impression rates
When it comes to digging into changes to your top and absolute top impression rates, it’s useful to graph them out over time. This will let you see those changes with the relevant time frames for analysis.
There are many ways to graph top impression rates from time to CPA, CPC, conversions, versus impression shares, and other methods. This will help you see the trends in your top impression numbers, and compare them to your quality score and CPC graphs.
Wrap-up
When your lost search impression share (rank) or your top and absolute top impression share metrics change, there are four primary ways to dig into the data:
- Graphing your quality score over time to see if a change in quality score affected your impression share.
- Examining CPC or bid method changes to see if your CPC has changed and affected your ad rank.
- Looking at any new or changed targeting methods, from keywords, audiences, time of day, demographics, and other options.
- Always making sure you have the recommended number of assets (ad extensions).
By looking into these four items, you can diagnose why your lost search impression share rank or top impression share metrics changed. You can then put a fix into place to ensure you’re always showing your most profitable ads.
For more on how to monitor KPIs and diagnose other data changes, please see our blog series.
For automated KPI monitoring and data analysis, as well as 40+ other PPC management features, please consider a free trial of Adalysis.
