The digital economy has substantially reduced market frictions but also posed new challenges for the efficient functioning of markets. In particular, the drastic reductions in the costs of search, entry, transportation, and reproduction have profound implications for the role of platforms, the value of innovation, and the balance between firms' data needs and consumer privacy. I review some recent economic research that sheds light on these issues, and discuss how well-designed policies on competition, regulation, IP protection, and consumer privacy can improve market performance in the digital economy