A system and method of transmitting data via a computer network to a plurality of end-users. Transmission of successive data units may be prompted by human-operated and/or automated central control. Successive arrays of data units may be transmitted over a plurality of channels, in parallel. Each end-user chooses which channel or channels to receive and may change channels at will. Transmission of successive arrays may coincide with successive occurrences during the course of a live event. Data units also may be transmitted over one or more channels asynchronously with transmissions over other channels. Controller-prompted transmissions, received passively by end-users, also may be integrated with a facility for end-users to browse data sources in a self-directed sequence and pace.