Quality Score Debunked

Google Ads gurus refer to Quality Score as king of the key performance indicators (KPIs).¹ In fact, it is considered by many to be the single greatest indicator of an ad’s overall effectiveness, as Google itself values quality over bid during auction. Although low quality scores can have considerable impact on a campaign’s cost metrics and performance, they are frequently overlooked or misunderstood by advertisers. To capitalize on the significance of Quality Score, advertisers need to understand the ins, outs and what-ifs that surround this particular KPI.

What is Quality Score and how is it calculated?

Google encourages advertisers to think of Quality Score as a predictive indicator of real-time auction performance. By aggregating and analyzing past auction data, Google assigns Quality Score on a scale of one to 10, with 10 being the highest grade attainable. When calculating this metric, Google Ads takes three items into consideration:

  • Landing Page Experience: How relevant and useful is the landing page to the user who clicked through your ad?
  • Ad Relevance: How well does the ad relate to the keywords contained?
  • Expected Clickthrough Rate (CTR): What is the likelihood that your ad will be clicked when it is shown?

The exact weight of each component remains a closely-held secret, although many have tried to reverse engineer it. The hypothesis is that expected CTR is the most influential metric, although some argue that expected CTR and landing page experience are weighted equally at 40% each.² 

To determine the above metrics and calculate Quality Score, it is necessary to accrue account history. At RentPath, we make sure to inform our new PPC clients of the Google Ads learning period, and that there is a threshold of impressions or clicks that must be met before Google Ads has enough data to determine landing page experience, ad relevance and expected CTR. Since your quality score is an aggregated estimate of your overall performance in ad auctions,³ keywords found in ads with little or no impressions/clicks will report a null quality score (signaled by “-”).

Where can I view Quality Score?

Only one component of your Google Ads campaign receives a visible and reportable quality score: keywords. 

Each keyword receives its own, individually-assigned score. However, this metric can vary if a single keyword is being used across multiple ad groups or campaigns. This is because landing pages, targeting settings and ad creative (copy, imagery, structure/type) typically fluctuate from one ad group or campaign to another, and each of these items heavily influences the Quality Score power trio (landing page experience, ad relevance and expected CTR). 

Keyword quality scores viewed at the campaign or account level represent a performance average across multiple variables, making it difficult to narrow in on factors that contribute to success. Alternatively, viewing Quality Score at an ad group level affords you the most intimate estimate of a keyword’s performance. This enables you to segment campaigns by specific areas of strength or weakness and empowers you to edit ad elements or copy accordingly. 

Why is Quality Score important?

A common misconception about Quality Score is that it’s used to determine ad rank and actual cost-per-click (CPC). While Google says Quality Score itself is not used at auction time,³ advertisers do tend to see higher ad rank and lower costs-per-click associated with keywords that have high quality scores. This is because the Quality Score metric is a highly accurate, predictive performance estimate

Google uses real-time assessments of clickthrough rate, ad relevance and landing page experience to calculate ad quality during auction, while Quality Score represents aggregated past auction-time performance data. Since Google values user experience and quality over bid during auction, Quality Score is an excellent indicator of real-time and future performance metrics. 


An advertiser’s first priority should be to optimize their accounts using Quality Score as the heartbeat of their campaigns. Higher quality scores typically lead to lower costs and better ad positions, as ad quality is the number one consideration in determining ad rank and cost-per-click. Although this alone should be plenty incentive, studies have also shown that cost-per-acquisition (CPA) may be strongly correlated with Quality Score as well. In fact, it is speculated that for every single digit increase in Quality Score above 5/10, there is a 16% to 22% decrease in the CPA.¹ 

Knowing this, it can easily be said that Quality Score’s massive influence on campaign health is undeniable. As a client, you should absolutely know and care about this KPI. As an advertiser, RentPath understands that Quality Score optimization is the most important and most cost-effective strategy for improving a client’s overall performance. Bringing attention back to the user experience not only enables renters to make an empowered decision, but enables us to achieve the highest level of performance possible. 

¹ “All Hail Quality Score – King Of The AdWords KPIs!” Larry Kim, 11 July 2013.
² “Reverse-engineering AdWords Quality Score factors” Brad Geddes, 9 March 2016.
³ https://support.google.com/google-ads/answer/156066#QSvAR

By Ashley Shaw, Sr. Digital Marketing Analyst

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