A numerical score Google Ads assigns to various account components (e.g. campaigns, ads), but only shows to account holders for keywords. Quality Score shows on a 1-10 scale. While Google doesn’t give out its exact formula, the three main components are: ad quality (judged by historical click through rate and normalized for position to estimate an expected CTR); ad relevance (including the use of ad extensions); and landing page experience. At a basic level, the higher your QS, the higher your ads can appear at both lower bids and actual costs per click.