Quality score (QS) is a 10-point measure applied at keyword-level within your search marketing campaign. As your quality score increases (typically as your campaign settles down over the first few weeks) you can normally expect to pay a slightly lower cost per click. This ensures that Google is not a pure auction model and that you can potentially enjoy a higher position than a given competitor whilst paying a lower CPC.
There are various measures that are used to calculate QS, but ultimately Google defines the core components of quality score as:
- The historical click-through rate (CTR) of the keyword and the matched ad 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 destination 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.
- Other relevance factors.