Recent information systems (IS) publications reveal an emerging interest in studying postadoptive system use behaviors. Compared to the well-established research stream of IS adoption and initial usage, understanding of IS use behaviors after initial implementation stage is still at its early stage. To further develop knowledge about this phenomenon, this study reviews the IS implementation stage model and a variety of post-adoptive usage concepts in extant literature. These usage concepts are classified into three types and are mapped against their corresponding implementation stages. A two dimensional view of these use concepts is then proposed as an alternative perspective to understand these post-adoptive behaviors. Implications are also discussed at the end of this paper.