Using the lens of early modern social authorship and contemporary social media, this Element explores a new print genre popular in England at the end of the seventeenth and early eighteenth centuries, the periodical. Traditionally, literary history has focused on only one aspect, the periodical essay. This Element returns the periodical to its original, complex literary ecosystem as an ephemeral text competing for an emerging audience, growing out of a social authorship culture. It argues that the relationship between authors, publishers, and audiences in the early periodicals is a dynamic participatory culture, similar to what modern readers encounter in the early phases of the transition from print to digital, as seen in social media. Like our current evolving digital environment, the periodical also experienced a shift from its original practices stressing sociability to a more commercially driven media ecology. This title is also available as Open Access on Cambridge Core.