If you don’t have a mobile-friendly website, start there. A mobile-friendly website adjusts to the screen size of the device being used. In the past, all traffic came from large computer monitors, but with the advent of the smartphone and the rise of tablets, a site that adjusts to different screen sizes is now imperative.
For additional incentive to make your site responsive, in the year 2015 Google made mobile-friendliness a ranking signal. Mobile-friendly sites now rank higher than non-responsive sites in Google search results.