This paper examines the evolution of citizen coproduction in the age of social media, web 2.0 interactivity, and ubiquitous connectivity. The paper first discusses the re-emergence of citizen coproduction - whereby citizens perform the role of partner rather than customer in the delivery of public services - as a fashionable policy option in the face of persistent budget deficits and the advent of new channels for mass collaboration. Finding a plethora of competing labels, models, and concepts for coproduction in the age of social media, the paper proposes a unified typology to support systematic analysis based on the overarching categories of "Citizen Sourcing," "Government as a Platform," and "Do-It-Yourself Government." To demonstrate its use, the typology is applied to leading U.S. government implementations. The paper concludes with a discussion of the potential implications for public administration, the remaining limitations and rising social concerns, and the possible emergence of a new social contract that empowers the public to play a far more active role in the functioning of their government. (C) 2012 Elsevier Inc. All rights reserved.