90% of all American house holds have cell phones, and in most cases every year mobile data usage (using internet on a mobile device) doubles in number of subscribers. As mobile data plans become more and more accessible, expect more people to look for your website on their phones. Having a mobile site is a huge plus (especially if your business is your website) and it doesn't hurt to be ready.
Talk to our friends at Inreact, and get a free quote on your mobile design.