Starting April 21 Google will be expanding their use of mobile-friendliness as a ranking signal. This change will affect mobile searches in all languages worldwide and will have a significant impact on search results.
The new algorithm will be emphasizing a lot on sites using responsive web design. Google has officially made it clear that Responsive Design is preferred design pattern for Google bots and sites, and the rest will have to battle a lower ranking.
Why this matters to you
To give you an idea of the importance to rank highly on a mobile device search, it is estimated that about 50% of all searches done on Google are now done on a mobile devices.
The big takeaway from this is that if your site is not mobile-friendly, get to work now on it!.
If 50% of your traffic from Google comes from mobile devices, if you are not mobile-friendly that virtually all of that traffic from mobile is at huge risk.