Mobile devices have made it possible for people to shop anywhere, anytime, and apparently, they’re taking advantage. According to Millward Brown Digital, people who shop from their mobiles visit more retailer sites than those who shop from their PCs (6.2 retailer visits per month on mobiles versus 2.9 on PCs). Mobile shoppers also use search engines and social media sites more than PC shoppers do. With all that opportunity to capture mobile purchases (or lose them to rivals), there’s all the more reason for retailers to make sure their mobile strategy is airtight.