Webster describes factors that create audiences, including preferences and habits of media users, the role of social networks, the resources and strategies of media providers, and the growing impact of media measures--from ratings to user recommendations. He shows that the marketplace works in ways that belie our greatest hopes and fears about digital media and shows that public attention is at once diverse and concentrated--that users move across a variety of outlets, producing high levels of audience overlap. He questions whether our preferences are immune from media influence, and he describes how our encounters with media might change our tastes. Webster claims we typically encounter ideas that cut across our predispositions. In the process, we will remake the marketplace of ideas and reshape the twenty-first century public sphere. -- |