Abstract: An advertisement annotation system includes a media player (50) and a remote database (20). The remote database (20) is arranged to store annotations and index data associated with advertising media data. The media player (50) is arranged to output advertising media data to a user and is responsive to receipt of instructions to output the advertising media data to obtain annotations and index data associated with the advertising media data from the remote database (20) and to output the or each annotation during output of the advertising media data in dependence on the respective index data. An advertisement annotation method is also disclosed.