Google also rewards websites by reviewing a site’s usability on a mobile device. Google’s Mobile Site Review analysed websites across Europe to determine their mastery of mobile.
Google's Mobile Site Review analyses over 300 websites across a variety of industries

As a Sitecore Platinum Partner we're extremely pleased that two websites we're closely associated with, Nationwide and The AA, have received high rankings in Google’s Mobile Site Review of Finance websites.
In the User Experience category, Nationwide achieved 78% and AA Insurance achieved 86%. In addition, the AA insurance homepage and navigation, as well as its Product pages, each achieved a maximum score of 100% at each stage of the customer journey. These are extremely encouraging and early results for two of the largest companies in the United Kingdom. It shows by taking a mobile first approach great things can be achieved.