A few months ago, Brad Geddes shared an insightful presentation about Quality Score analysis at SMX Advanced. He recommended that companies analyze both CPC and CPA by Quality Score to help determine if the time spent to improve Quality Score would really be worth it. Bethany wrote a great post recently explaining why Quality Score is not a KPI. While I agree with her that this is true, I still wanted to utilize Brad’s analyses to see if the correlation between low Quality Score and high CPCs and CPLs was strong enough to warrant some work to help improve this metric in my accounts.
The Data
I decided to review keyword performance for two of my bigger spending clients over the past 30 days. I should note that the data set for the first account does include branded keywords while the second one does not (Branded terms are housed in a separate AdWords account). I removed keywords with zero clicks and created pivot charts for the following: average CPC by Quality Score, average CPA by Quality Score and Sum of Clicks by Quality Score. I wanted to not only see the strength of the correlation between CPC and CPA by Quality Score but I also wanted to know what percentage of clicks for each account was associated with what Quality Score number. For instance, if CPC and CPA were significantly higher for low QS terms but the percentage of total clicks was extremely low then the impact of Quality Score improvement for such few terms on the account would be relatively small and therefore would likely not be worth the time spent to improve QS for those terms.
Account 1 Analysis
Let’s take a look at the data for the first account.
When looking at the trend line for this chart, there does appear to be a correlation between lower CPC and higher Quality Score, with 1’s fairing just above a $6 avg CPC and 10’s fairing just above a $4 avg CPC. Yes, an approximately $2 difference is pretty significant, but let’s take a look at the CPA data.
Here we appear to see a much sharper decrease in the trend line, however upon removing the handful of 9 QS keywords the line becomes much flatter:
There are some notable outliers with the 6’s having the second lowest avg. CPA (when including the low CPA 9s), and with the 7s having the highest overall avg. CPA. It would appear we have some action items for this account, but let’s review the sum of clicks by Quality Score:
The bulk of the clicks in the past 30 days have been on QS 6 terms; this makes sense since this is the default QS number for new keywords. Considering that 56% of total clicks are on keywords with QS of 5 or below, some improvements should be made to help improve QS on those terms. Additionally, I will want to look especially at the QS 7 terms due to their high overall avg CPA; for instance, I’ll review the search terms associated with these keywords to help ensure relevancy, I’ll review ad copy for these ad groups and also landing pages to help ensure barriers to conversion are removed or minimized.
Account 2 Analysis
Let’s take a look at the data for the second account.
As with the first account, there does appear to be a correlation between lower CPC and higher Quality Score as we can see a general downward trend, and the variance again is about $2 difference between the lowest and highest avg. CPCs. 
In terms of avg. CPA by Quality Score, we see a very sharp decrease in CPA as Quality Score increases, with a noticeable drop off in CPA starting at Quality Score 6. Let’s review the sum of clicks by Quality Score for this account:
The bulk of the clicks in the past 30 days have been on QS 3 terms, and this isn’t favorable news since QS 3 terms also have the second highest overall avg. CPA. Additionally, even though branded terms are not included in this account’s data, considering that a whopping 95% of total clicks are on keywords with QS of 5 or below means that this account could greatly benefit from some Quality Score TLC. I will especially want to take a look at the QS 5 terms as they have the highest overall avg. CPA and it’s significantly higher than the avg. CPA for other QS levels.
My Takeaways
Sometimes I think the pendulum can swing too far one way or the other on debated issues, and Quality Score and the need for our attention to it is one of those issues. Quality Score is not a KPI, but it does deserve regular analyses like this one. Ultimately, these charts didn’t take long to put together and gave me valuable insights into both accounts. Although Account 1 doesn’t need quite the deep dive Account 2 needs, I was able to glean some valuable action items that won’t take too long to execute. I’d encourage you to take a few minutes and analyze your accounts as well!
What about you? What type of Quality Score analyses have you found helpful for your accounts? Let us know in the comments below!
