As both computer and mobile phone reach nearly ubiquity in the U.S. market, the slow uptake of mobile video, in contrast to the thriving usage of PC-based video, warrants a deeper understanding of user-oriented factors contributing to the two diffusion paths. Unlike the majority of existing diffusion research practices, the dissertation examines the differences between mobile and PC video diffusion patterns through the lenses of user-oriented influences in the user-technology relationship. Built upon the established adoption user group classification, the research is informed by the Uses and Gratification theory, the Social Technical theory, and the Technical Affordance perspective. These synergistic theoretical arguments share the recognition of the role of user in the dynamic, usually socially intertwined user-technology interactions. The key research questions that the dissertation sets out to answer include: Does the importance of quality of viewing experience in adoption decision for PC video and mobile video differ significantly across the adoption groups? Do the adoption groups have different expected technology affordances or discover technology affordances different from expectation after experiencing the technology by mode of video? Results suggest PC video has significant advantages over mobile video in terms of a broad range of affordances--convenience, space and user-creativity related affordances. Particularly, higher level of affordance is expected and experienced toward PC video among Early Adopters/Early Majority, usually equivalent to the critical mass for any technology, signaling the need for a stronger push for relevant affordance for mobile video. The research reports a strong, positive correlation between expectation and actual experience of technology affordance for both mobile and PC videos, which implies a phenomenon of "expect it, and you'll find it." There is also some evidence to show that this correlation is even stronger among later adoption groups, underscoring the paramount practice of building positive expectations for mobile video among the mass market in order to achieve critical mass for adoption. The dissertation reveals how users acquire or identify affordances as related to mobile and PC videos in the adoption process. Trial and error is found to be the most frequently leveraged channel to discover affordance. Despite a few subtle differences across market and adoption groups, social exchanges and information seeking are also highly utilized channels for both video technologies. The user's reliance on the above channels together with the significant presence of false affordance, unexpected affordance and unusual affordance clearly illustrate the relational nature of technology affordance involving the user and the technological artifact. This understanding is needed for mobile video marketers to best align technology development, promotion and support efforts to catalyze the market acceptance of the technology. Further delving into the formation of false and unexpected affordances, the research indicates some evidence that the cue-heuristic-affordance connection can be used to reduce dissonance in user experience, and hence facilitate user adoption. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]