Abstract: Systems and methods are provided for generating user format preference data and using that data to select and/or deliver a specific format of a work. For example, a dynamic format delivery service can dynamically collect data representing a user's preferences respecting specific contexts and formats, and can store this data in association with the user. The dynamic format delivery service can then make use of that data to dynamically select a format for a requested work in order to provide the user with a format tailored to that specific user's consumption habits. Moreover, data representing preferences of a population of users, context attributes, or device-specific format preferences may further contribute to selecting a work format.