As of April 21st, if your site isn't mobile friendly, you may find it harder to rank in Google’s mobile search results. Websites that offer a consistently strong experience for users regardless of screen size will see an improvement in ranking performance when compared against those that aren't 'mobile friendly'.
We've been talking about the importance of responsive web design a lot recently. With Ofcom reports showing that mobile and tablet users outnumber desktop and laptop users when accessing the internet (a 52% - 46% split) it is shocking to learn that only 1 in 8 websites are thought to be responsive.
With Google's Mobile Friendly Algorithm upon us, you can find out the likely impact on your site using this brilliant little guide from Search Engine Land searchengineland.com