This paper examines the implications for research on the diffusion of innovations (DOI) arising from a growing body of literature in two related fields. The first area concerns the debate on the role of regional and national systems of innovation in the innovation process. The second area deals with the argument that enterprises must move from a “closed innovation” to an “open innovation” paradigm. The review is presented in the context of a case study being undertaken in a subsidiary of American Power Conversion (APC) located in the West of Ireland. Based on the preliminary stages of our work, we present a conceptual 3-D model of Rogers’ innovation-decision process and suggest a series of propositions to stimulate future research efforts.