Statistics show that more people are going “mobile only” -- either because they never had a desktop or because they won’t replace their existing desktop. Additionally, a non-mobile-friendly site may not see many mobile visitors precisely for that reason.
On April 21, 2015 Google, Yahoo, Bing, Ask and AOL rolled out a mobile-friendly change in their index, this change dramatically affects any website which isn't mobile responsive. This mobile-friendly change applies to mobile searches conducted across all sites, regardless of the site’s target audiences’ language, region, or proportion of mobile to desktop traffic.
