Impressions on Click Through for a Quality Score

My earlier post Average Position & Quality Score of AdWords Click Through focused on Average Position and how it relates to a keyword’s Click Through Rate (CTR) and Quality Score. What it did not address was how Click Through Rates and Impressions related to Quality Score and Cost Per Click.

The data used in the last blog post demonstrated that Quality Scores of between 7 and 10 featured prominently in Average Positions of 3.9 and higher, and that the bulk of impressions the campaign received were a result of terms with a Quality Score of 7 or higher, barring one outlier at Quality Score 4 in the dataset.

Impressions for Quality Score or Impressions for Keywords

That most Impressions occurred through a Quality Score 7 or higher keyword becomes less remarkable once the number of keywords at each Quality Score is considered. An easy majority of the keywords from the data used in the original blog post had a Quality Score of 7 or higher.

How do the keywords with a Quality Score of 7 differ from those at other levels? Google has publicly stated that Quality Score is calculated using a number of factors like:

• The historical clickthrough rate (CTR) of the keyword and the matched ad on Google; note that CTR on the Google Network only ever impacts Quality Score on the Google Network — not on Google
• Your account history, which is measured by the CTR of all the ads and keywords in your account
• The historical CTR of the display URLs in the ad group
• The quality of your landing page
• The relevance of the keyword to the ads in its ad group
• The relevance of the keyword and the matched ad to the search query
• Your account’s performance in the geographical region where the ad will be shown
• Other relevance factors

Ignoring the “don’t be an idiot” factors such as landing page quality and relevance of the keyword to the ads in the ad group, Quality Score is mostly influenced by the performance of the search terms, the keyword, the ad and your own account history.

Impressions, Quality Score, Click Through Rate and Cost Per Click for Quality Score 7

Quality Score is strongly associated with the Click Through Rate (CTR) on the exact match of the keyword in the campaign. It is not easy to get to this data through AdWords, either online or with their desktop tool, and usually requires a little work in a spreadsheet.

The dataset use for an Impure.com workspace compares the keyword’s exact match Impressions, CTR and Cost Per Click (CPC) with those listed for all searches it accounts for. The exact match data was acquired through the all search term report available through the AdWords account management site.

For keywords with a Quality Score of 7, there is a relationship between the exact match Impressions it receives and the CTR it has. Keywords at this Quality Score with more impressions tend to have a lower Click Through Rate than those with fewer. This pattern does not hold for the Click Through Rate of all impressions triggered by the keyword.

The relationship between exact match Impressions and CTR also exists for Cost Per Click. Keywords with more Impressions also pay less per click. Again, once you use data for all Impressions triggered by the keyword, this relationship seems to disappear.

For the campaign examined, it appears that it is the volume of Impressions that the keyword receives for a Quality Score of 7 that can influence CPC as much as Impressions. However, the relationship this has with the cost for all clicks received as a result of phrase or broad match is a little unclear.

Regarding Quality Score as a bulk discount rather than a relevance score is a more meaningful perspective. At least within the dataset used and for a Quality Score of 7, the more Impressions and the better the Click Through Rate, the cheaper the traffic.