This detailed literature review has considered a relatively large quantity (152 total) of scholarly empirical publications, conference proceedings, books and popular market reports published over the last 15 years, i.e., from January 2000 to December 2014, in the field of human continuous usage behavior and in the context of information technology/systems. Based on the search results, the literature was synthesized, segregated into four major domains according to the purpose, nature and usage of the information technology/systems. The authors believe that this segregation within the information technology & systems continuous usage literature provides greater scalability, flexibility and space for future research. Moreover, this proposed segregation allows for future research to include more ‘systems’ in each category depending on the usage, relevance and nature of the ‘systems’ that will evolve over the period of time. Scalability will provide more insights and ideas that will help future research investigate and propose domain-specific conceptual or business models that will help facilitate an understanding of information technology/systems continuous usage according to the nature of the ‘system.’ Conclusions and recommendations are drawn and priorities are proposed for continuing research.