Digital media offer countless options that compete for a limited supply of public attention. The patterns of use that emerge in this environment have important social implications, yet the factors that shape attendance are not well integrated into a single theoretical model. This article posits such a theory using Giddens's notion of structuration as an overarching framework. It identifies public measures that distill and report user information as a pivotal mechanism that coordinates and directs the behaviors of both media providers and media users, thus promoting the duality of media. The theory is then used to understand evolving patterns of public attention in the digital media environment.Digital technologies offer a seemingly endless supply of media that compete for public attention. Commentators have variously celebrated or decried this new world of media, though all seem to recognize that patterns of use will be central to understanding the media's social impact. This article argues that public attention is the result of a structurational process in which institutions and users mutually construct the media environment. Central to this process are two types of public measures. The first, market information regimes, provide media institutions with the data they need to monitor and respond to the marketplace. The second, user information regimes, are new measures that offer consumers tools to navigate the digital environment. All such regimes are socially constructed and potentially biased. Increasingly, though, they determine how things come to public attention.To explore the forces that shape public attention, this article proceeds in four sections. First, it defines public attention and makes a case that it is an important, but underdeveloped, concept in media studies. Second, it outlines a theory of public attention that is derived from Giddens's (1984) work on the duality of structure and the literature on media industries and audience behavior. Third, it demonstrates the ways in which public measures affect the duality of media systems. Finally, it considers how structurational processes shape three socially consequential patterns of