The fourth-generation mobile phone soon will be launched. Marketers are concerned about customer acceptance, and, in particular, about the main factors that determine whether customers will upgrade their mobile phones, which will affect the diffusion of 3G, 4G, and Worldwide Interoperability for Microwave Access phones. We integrated post- and pre-adoption theories, upgrading and value-based theory and chose 2G and 3G users to examine customers' plans to upgrade their current phones, and found that value assessments can affect mobile users' plans to upgrade to next-generation versions. When 2G mobile users were satisfied with their current model, they were not willing to upgrade to 3G mobile phones. They tend to upgrade by leapfrogging the next generation product as an indirect result of their positive satisfaction with their current model. These results suggest that 2G mobile users consider the 3G mobile phone to be a transitional product, and will wait for future options that are expected to perform better than those presently available.