A multimedia apparatus, such as a set top box for use with a television set, comprises a receiver for receiving program data from a communication channel and a processor which stores said program data with a file containing associated secondary program data, such as a promotional trailer. The processor compiles a menu of secondary program data files allowing a viewer to watch a trailer and decide whether to retrieve the full program or film. The secondary data may be broadcast in parallel with the program data. Alternatively, the processor may run an application for producing the secondary program data, e.g. using earmarked portions of the full program data.