Drawing on work done in the multi-project Research Unit "Popular Seriality—Aesthetics and Practice" (DFG-Forschergruppe), our paper presents five interlinked analytical perspectives on commercial serial storytelling. We argue that popular series and serials are best described as (1) evolving narratives: they exist not so much as structures that have been designed but as entities that keep developing in adaptive feedback loops with their own effects. (2) Hence, practices of recursivity, such as the continual readjustment of possible continuations with respect to what has already been narrated, are essential to serial storytelling. (3) Commercial series and serials can be examined as narratives of proliferation, because they tend to expand beyond the bounds of their original core texts. (4) Thus, it is helpful to think of popular-serial practice according to the Latourian model of actor-networks. Following this model, popular series and serials can be analyzed as self-dynamic cultural agents, comprised not only of acting persons and institutions but also of action-conducting forms, objects, and media. (5) Consequently, a cultural-ecological approach is well suited to describe the development, since the 19th century, of commercial series and serials in correlation with the evolving affordances of their technological and ideological environments.