We knew it was coming. It was only a matter of time before consumers started to rely more on mobile devices to browse and shop with retailers online, and the shift is definitely in full swing. A few recent studies shed light into where and how fast the shift is occurring, but the bottom line is, if your site’s not mobile-ready (or you’re not in the process of making it mobile-ready), you’re falling behind. The first place to look at the overall trend is the proliferation of mobile devices and decline of desktops and laptops. PC sales are down across the board and according to data from research firms like Gartner and IDC, fell between 9.5 and 11.8 percent during the second quarter of this year. And at the same time, smartphone use is booming. comScore’s recent Global Mobile Platform Report revealed that 61 percent of total digital media time in the U.S. is spent with smartphones and tablets. Compare that to only 39 percent of time spent on desktops. Drilling down more specifically into ecommerce, the trends are the same. One of the most important things to note is just how significant smartphones have been in driving the shift. They’re leading the charge in mobile ecommerce traffic and are now drawing 25 percent more than tablets, a lead that was extended significantly from 14 percent a year earlier according to mobile developer Branding Brand. Data from Demandware is another validation. Among its customers, the company has seen smartphone traffic in the U.S. increase by 33 percent while PC traffic fell 8 percent and tablet traffic was down 13 percent. We’re still a long way away from total mobile domination because 69 percent of orders still come from computers, while only 18 percent are from smartphones and 13 percent are from tablets. But the tide is definitely turning. When these statistics are compared to the previous year, PC orders are down 8 percent and tablet orders are down 5 percent. Once again, smartphones shine with a whopping 58 percent increase. There are a lot of factors at play driving these trends. The uptick in mobile shopping is partly driven by things like improvements in wireless broadband, smartphones with bigger screens that make shopping and browsing easier, and the growing purchasing power of aging millennials who are tied to their mobile devices. On the other hand, retailers are doing their part to stoke the mobile commerce flames by rolling out sites that provide a better mobile experience. Both sides of the market – consumers and retailers – are driving this bus together, but retailers definitely have the most at stake. They need to make sure they’re ready for mobile commerce, or they risk being left in the past.