Digital learning makes possible the "unbundling" of school provisions--that is, it allows children to be served by providers from almost anywhere, in new and more customized ways. At the same time, because it destandardizes and decentralizes educational delivery, digital education is far harder to bring under the yoke of the quality-control systems and metrics that have been devised for traditional school structures. In this paper, Hess explores the pros and cons of input regulation, outcome-based accountability, and market signals as solutions to the quality challenge. In the end, he recommends using all three approaches in careful combination so as to leverage their strengths and offset their weaknesses. In practice, that means demanding transparent financial information from providers, holding them to account for student achievement gains whenever possible, and developing "crowd-sourcing" reporting systems to help educators, parents, and students identify the most effective purveyors of online learning. (Contains 14 footnotes.)