Is Quality Score REALLY Just Click-Through Rate?


If you are looking to improve your Quality Scores in AdWords, almost every single PPC expert will start by telling you to take steps to improve your click-through rate. No surprise there. Google has not been shy in sharing that CTR is the most influential metric used in calculating your Quality Score, and our own internal studies back this up.

The only question is, how influential?

I have heard speculations as high as 60%. However, if that were true, it would not explain why you see keywords with a great CTR and only a mediocre Quality Score. Of course, the real answer is much more complicated.

Take a look at this graph showing the relationship between click-through rate and Quality Score for ads in the top position:

quality score for top position

If you look at a plot between CTRs and their respective Quality Scores, you will see the relationship between the two takes on a logarithmic trend rather than a linear one.  This means that as click-through rate increases, it has less and less of an impact on your Quality Score. In economics, we call this the law of diminishing returns.

Let’s look at a mathematical example. Say your actual search network CTR is 2% with an average QS of around 4, but your expected CTR is 4%. You make changes in your account to bring your CTR up two percentage points to meet the average. Following the trend line, you can expect your keyword QS to jump 1.5 points to an average of 5.5.

But you want to be above average! Now you work to improve your CTR up another two percentage points to 6%. This time your QS only jumps 0.7 points to about 6.2. In fact, to see the same return on Quality Score, you will need to double the expected CTR from 4% to 8%. You’d need to quadruple the expected CTR to get to an average QS of 8.

So summarize, if your actual search network CTR is below expected, making changes to improve it can significantly increase your Quality Score. However, once you have achieved an expected click-through rate, you can make HUGE improvements to your click-through rate and only see minimal improvement in QS.

check expected ctr in adwords


[Pro tip: You can check how your individual keywords compare to their expected CTRs in AdWords by hovering over the speech bubble next to a particular keyword on the campaigns page. Google offers a prediction of below average, average, and above average.]

Feeling defeated? DON’T! Your still have options when it comes to improving account performance:

Give it Some Time.

Quality Score doesn’t change overnight. Google looks at your account history when making Quality Score calculations, so a few weeks of improved CTR isn’t going to wash away months and months of poor performance. I would never recommend letting your account run on autopilot, but if you make it a priority to actively monitor your account (as you should), remember that it’s going to take some time for these metrics to reflect all your hard work. Don’t write off your Quality Score hopes and dreams too early.

Use Ad Extensions.

If you aren’t using them already, ad extensions are a double whammy when it comes to improving your QS. Google now includes the presence of ad extensions when calculating your Quality Scores. If that weren’t incentive enough, they also increase your click-through rate by occupying more space on the SERP, which in turn boosts your QS ever further!

ad extensions and quality score

Sitelinks, for example, are super simple to set up and give the searcher several pathways to get to your website.

Improve Your Landing Page Experience.

It can be too easy to forget about this component of your Quality Score. In fact, 25% of AdWords advertisers send all of their PPC traffic to one single page. Be sure to have unique landing pages with content that is highly relevant to your campaigns. Landing page copy should include high-performing keywords in relation to your ad groups and ad text.

Revisit Your Goals.

People like to look at Quality Score because it is an indicator of several aspects of account performance, but chances are your goal isn’t to increase Quality Score just to prove that you can manage AdWords better than everyone else. Take a step back and analyze why QS is so important to you in the first place. Are you trying to make the most of a limited budget? Do you want your ads showing at the top of the page? Take a look at other metrics that directly correlate to your goals and optimize from there.

Just remember PPC is a marathon, not a sprint. Quality Score is a direct reflection of that; making improvements to CTR is a great place to start but it won’t get you to the finish line on its own. Try to avoid Quality Score tunnel vision by looking for other measurable ways to define success for your search campaigns!

About the author:

Jess is a Customer Onboarding Associate at WordStream. She spends her free time binge-watching the Food Network and making her friends taste her culinary creations (usually to their delight). Occasionally, she can be spotted doing handstands in an unnoticed corner of the room.

Twitter: @Jess_Armstrong_

Linked In:

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Steve Cameron
Mar 26, 2015

Interesting numbers. I have recently found that tighter geo targeting on a campaign gave a higher QS - compared with the same keyword in a cloned campaign with looser geo targeting. At all levels it would seem that the more relevant you are (keywords, ad copy, geo targeting, language targeting, etc) the better your QS will be. QS seems to be a numeric reflection of the relevance that Google sees between what the visitor is searching for and what you offer.

There is a lot more to QS than meets the eye - of course, one important thing to remember is that anything that you do to improve the campaigns - adding extensions, getting the segmentation tighter, better ad copy, are all likely to improve the CTR independent of the QS - so it sometimes becomes a case of chicken and egg, which came first?

I do feel, however, that often too much emphasis is placed on QS. As I mentioned above, QS is a reflection, not the source itself.

Jess Armstrong
Mar 31, 2015

Thanks Steve! I agree that sometimes too much emphasis is placed on quality score. At the end of the day, its about the bottom line and if you're hitting your numbers, then it's time to relax and let it go.
Great point about geo targeting!

Andreas Obermüller
Mar 26, 2015

Hi Jess,

Nice article about quality score, although I miss a (in my opinion necessary) reference to writing relevant ads - as being an important part of how quality score is calculated.

Who is better to explain what quality score is all about than Google Chief Economist, Hal Varian?
Although his video is from 2010 it still is valid.

And from my experience - writing relevant ads - can make the difference when your CTR is at an all high and your landing page experience is allready the best the visitors can get.

Great article though and thanks for taking the time to put everything together.
Especially the hint to the "the law of diminishing returns".

Thanks again,

Jess Armstrong
Mar 31, 2015

Hi Andreas! Great point. Writing relevant ads is crucial when it comes to both click-through rate and QS. Thanks for sharing!

Fernando De Los Santos
Mar 26, 2015

Great article, as always!

Steven Herron
Apr 08, 2015

Wondering if anyone saw this "glimpse" into Google's QS algorithm that was caused by a glitch over the weekend?

Elisa Gabbert
Apr 08, 2015

Interesting -- hadn't seen this yet!

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