Mobile user experience has been evolving over the course of the past decade, with a greater percentage of online searches being performed on mobile devices every year. Addressing this trend, Google has made strong efforts to accommodate mobile audiences, tailoring its search results to favor sites that are suitably optimized for mobile use. For example, a responsive-designed website will always perform better in search results than its non-mobile optimized counterpart in mobile searches, and mobile-friendly sites are marked with an appropriate “Mobile-friendly” tag in search results, increasing their click-through rate from search engine results pages.

The ranking boost you get from having your site optimized for mobile has been significant, yet not overwhelming. Millions of sites have fared just fine despite not being optimized for a mobile user experience, and yours may very well be one of them. Unfortunately, this respite will not last much longer.

As announced by Google in a recent blog post, Google is currently working on a significant structural algorithm change that will increase its emphasis on mobile-usability as a ranking factor. Once rolled out, the algorithm change is expected to have a significant impact on search results; Zineb Ait Bahajji, a member of Google’s Webmaster Trends team, was quoted at SMX Munich as saying that the new mobile-friendly algorithm change will have more of an impact on search rankings than either Panda or Penguin, two of its most impactful search algorithm updates Google has ever rolled out.

For more information go to this source http://www.forbes.com/sites/jaysondemers/2015/03/31/is-your-website-optimized-for-mobile-you-have-until-april-21-to-get-it-done/