E-commerce in the United States is growing, driven by increased online and mobile shopping. The proliferation of smartphones and tablets is boosting the time consumers spend shopping online and completing purchases via mobile devices. Large retailers are increasingly investing in their online sales divisions and building omni-channel experiences that integrate online and physical shopping. Existing online customers are spending more, rather than new customers, contributing to the growth of e-commerce. Major retailers and food companies are shifting their focus to online shopping and repositioning themselves, such as Amazon expanding into the grocery market with Amazon Fresh.