Diffusion and institutionalization are of prime sociological importance, as both processes unfold at the intersections of relations and structures, as well as persistence and change. Yet they are often confounded, leading to theoretical and methodological biases that hinder the development of generalizable arguments. We look at diffusion and institutionalization distinctively, each as both a process and an outcome in terms of three dimensions: the objects that flow or stick; the subjects who adopt or influence; and the social settings through which an innovation travels. We offer examples to flesh out these dimensions, and formulate testable propositions from our analytic framework that could lead to further theoretical refinement and progress.