“Starting April 21, we will be expanding our use of mobile-friendliness as a ranking signal. This change will affect mobile searches in all languages worldwide and will have a significant impact in our search results. Consequently, users will find it easier to get relevant, high quality search results that are optimized for their devices.”See: http://googlewebmastercentral.blogspot.ca/2015/02/finding-more-mobile-friendly-search.html
Take particular note the words.. “…will have a significant impact in our search results.”
It is therefore even more essential now that your webpages are optimised for not only desktop and laptops but also mobile devices including smartphones and tablets. By doing so you can be sure that visitors are getting the best user experience, and that your website rankings will not be adversely affected, and could in fact help them improve.