Social media are becoming a growing presence in our cities, filtering our experience of urban place and enabling locations to “go viral.” This article examines the downstream consequences of this new reality, examining how the urban actors who shape the city consider social media in their work. Drawing on ethnographic research and interviews with elite investors in São Paulo’s gentrifying Centro neighborhood, this article finds that social media are ever-present force in the production of the city. The capacity of social media to shape imaginaries and steer flows of people—and therefore flows of capital—have emerged as a powerful economic logic, integral to the city’s economic machinery. In pursuit of online attention, investors are adapting the city to fit their understanding of what “works” on social media—changing not only superficial designs and aesthetics, but even in which buildings they invest. Restaurants and bars come to function as intermediaries for the exchange of attention capital: they purchase attention from influencers, in turn marketing it to their customers and exchanging accumulated digital clout for free beer and new kitchens from their suppliers. Attention is transforming the very built environment of the city, which in turn provides essential physical infrastructure for the attention economy. While social media platforms may be diverse in their biases and characteristics, this article argues that the imperative of data accumulation has produced an era in which everything—even our cities—is shaped by the pursuit of attention.