More and more people are surfing for information on their smartphones, even if they have a desktop computer present. With mobile traffic taking a larger footprint in your traffic sources, it's more important than ever to have a mobile-friendly version of your site.
But that's not the only reason - Google has started indicating which sites are Mobile-Friendly in search results. As a smartphone end user, I'm more likely to click a link that I know is optimized for my device versus one that will leave me pinching, stretching, and otherwise frustratedly clicking BACK.
Admit it - this is you visiting non-mobile friendly sites on your phone
Google has dedicated a whole section of their webmaster area to helping you start to convert your site to mobile, what to think about, and even details the most common mistakes to avoid. They even have a site analysis tool that will tell you how your site looks now. It gives recommendations on the key elements to update to really maximize the mobile space.
Click Here for Google's Guide to
Making your Website Mobile-Friendly