On the 21st of April, Google began prioritizing their mobile search result based on mobile friendliness of the site code.? As Google Webmaster Blog puts it
Affects only search rankings on mobile devices!
Affects search results in all languages globally!
Applies to individual pages, not entire websites!
While the mobile-friendly change is important, Google still uses a variety of signals to rank search results. The strength of the content in which a search query is being made is very important — so even if a page with high quality content is not mobile-friendly, it could still rank high.
There are several implications to this move, first is that your site is better off if it has a mobile version. Whether you are inclined to use fully responsive or case responsive mobile site, your site needs to be responsive.
Second, is the continuation of their previous policy announced earlier this year. Google bots are looking at your site elements instead of your source code, so here again, the bot will scour through your style sheet to make sure that you have your mobile scenarios covered.
You may think that this will effect small businesses only, but if you look you may be surprised to find names such as Nintendo and Versace in the list of sites that Google does not find compliant.
Even though, the implications of this move?are not likely to be as great as all the early hype had indicated, it is still good to note that Google is modifying its algorithm not just for content, but to keep up with the times.
In order to give better guidelines, and provide helpful tools, Google webmaster blog has started the Mobile Madness Campaign (#mobilemadness). If you are interested, you should look at http://googlewebmastercentral.blogspot.com/2015/04/mobilemadness-campaign-to-help-you-go.html