Citizens and governments live increasingly digital lives, leaving trails of digital data that have the potential to support unprecedented levels of mutual government–citizen understanding, and in turn, vast improvements to public policies and services. Open data and open government initiatives promise to “open up” government operations to citizens. New forms of “big data” analysis can be used by government itself to understand citizens' behavior and reveal the strengths and weaknesses of policy and service delivery. In practice, however, open data emerges as a reform development directed to a range of goals, including the stimulation of economic development, and not strictly transparency or public service improvement. Meanwhile, governments have been slow to capitalize on the potential of big data, while the largest data they do collect remain “closed” and under-exploited within the confines of intelligence agencies. Drawing on interviews with civil servants and researchers in Canada, the United Kingdom, and the United States between 2011 and 2014, this article argues that a big data approach could offer the greatest potential as a vehicle for improving mutual government–citizen understanding, thus embodying the core tenets of Digital Era Governance, argued by some authors to be the most viable public management model for the digital age (Dunleavy, Margetts, Bastow, & Tinkler, 2005, 2006; Margetts & Dunleavy, 2013).