Search advertising: The primary contributing factor to quality score is click through rate (CTR)

Google assigns a 1-10 quality score to each keyword in a Google AdWords account which contributes to how ads are ranked on the Google search results pages. This quality score is said by Google to be an estimate of the quality of keywords, ads and landing pages with a specific focus on the relevance between these components.

Research and extensive data analysis have provided overwhelming evidence that the metric Google most heavily relies on to indicate relevance, is CTR.

A good quality score leads to cost savings

Quality score is a massively important metric when it comes to search campaigns served on AdWords. A high quality score can result in huge cost saving – and a great deal more traffic and likely conversions – to what can be attained with a low quality account at same budget spend.

This is because Google rewards advertisers with ads and content that are highly relevant to what the user has searched for. With a good quality score, a higher ad rank position can be attained at lower cost per click (CPC).

Ad Rank Quality Score

Fellow Saatchi & Saatchi Synergizer, Kevin Metcalf, has found that possible cost savings as a result of quality scores can result in 5.84% of budget saved when improving quality score with as little as one point.

If a client has a monthly media budget of R500 000, that would mean savings and media efficiency improvement of more than R29 000. Over a one year period, that will quickly add up to more than R350 000 of additional media spend being available.

Quality versus quantity

There is thus plenty of incentive to work towards – and maintain – a good quality score. Yet few search advertising agencies view this as a priority. Automated bidding rules and software are often touted as the be all and end all to remaining competitive in search rankings.

While automation does have a place in the industry, we frequently see it result in quality being compromised in favour of quantity. Mass scale bidding changes are implemented with little to no human interaction on accounts to accompany it.

I would recommend a more measured approach when it comes to managing search advertising campaigns. By having eyes on your search accounts and creating highly segmented campaigns – with ad text very tightly matched to keywords in narrowly themed ad groups – excellent click through rates can be achieved.

While common sense dictates that relevance (and thus quality score) is measured via CTR to at least some extent, our research and data analysis indicates that it is the sole most important metric to focus on if improving quality score is of importance.

Click through rate (CTR) is key to quality score

After conducting research in which more than 60000 keywords that have generated more than four million impressions and 175 000 clicks were analysed, a clear trend could be observed. There is a direct correlation between CTR, quality score and CPC.

As CTR increases, quality score improves, while CPCs decrease.

PPC Quality Score

Need help understanding the graph? The blue line indicates average quality score while the orange line reflects avg. CPC. CTR can be found on the x-axis – increasing from left to right on the chart.

Delivering the best returns for clients on search campaigns means getting a multitude of things right – there however few that are quite as important as securing an ace CTR.


Written and compiled by: Aimeé Schroeder

Twitter: @AimeeSchroeder


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