Google has made it pretty clear that soon (April 21st, 2015 to be exact) they are going to be ranking sites a little differently when searching from mobile devices, in essence ranking mobile-friendly sites higher than non-mobile formatted sites in the returned search results.
Now if your primary audience discovers your website via the desktop then this is all fine and dandy, but as we all know, most traffic sources these days are originating from mobile, given the current pervasiveness of mobile data – meaning that it is probably a good idea to ensure that your site is indeed mobile-friendly, lest you lose any Google brownie points!
To assist you in not losing any points unnecessarily, Google has released a helpful web-based tool to check whether or not your site is indeed mobile-friendly, helpfully named “Mobile-Friendly Test“.
In other words, if you are at all interested in things like this, then it is probably best you quickly nip off and run your sites against the tool.
Case in point:
Related Link: https://www.google.com/webmasters/tools/mobile-friendly/