1. A method for execution by a processing module of one or more computing devices associated with an on-line media storage system, the method comprises: randomly and continuously receiving, for storage in the on-line media storage system, data objects from a plurality of authorized users, wherein data type of a data object of the data objects is one of a plurality of different data types and wherein memory space within the on-line media storage system is primarily allocated to the plurality of authorized users on an as-needed basis; and processing the data objects for storage by entering a loop that includes: for the data object from an authorized user of the plurality of authorized users, determining a system level storage efficiency preference based on system storage node information and one or more of: the data type of the data object, data size of the data object, identity of the authorized user, location of the authorized user, system privileges of the authorized user, storage preferences of the authorized user, and user group affiliation of the authorized user; selecting a set of storage nodes from a multitude of storage nodes of the on-line media storage system based on the system level storage efficiency preference; determining dispersed storage error encoding parameters based on the set of storage nodes or based on the system level storage efficiency preference; encoding the data object in accordance with the dispersed storage error encoding parameters to produce encoded data slices; generating system addressing information for the encoded data slices based on the encoded data slices, the set of storage nodes, and identity of the data object; updating a user profile for the authorized user to include the system addressing information for the data object; and repeating the loop for another data object from another authorized user of the plurality of authorized users as the data object from the authorized user.