Currently, 1.75 billion people in the world own a smartphone. And for the first time in history, commerce on mobile devices has surpassed online shopping via desktop. If the proliferation of app purchases for mobile devices is any indication (e.g., Apple's New Year's week record-breaking $500 million in sales), 2015 is going to be the year for businesses to capitalize on mobile commerce. Here are three tips on how to stay up to speed and capitalize on the mobile opportunity: