A method and an apparatus (1) for transmitting advertisement data to a receiver (20) of each viewer/listener registered with a transmitting side are provided. In the transmitting side, from each registered viewer/listener, data characterizing a group to which the viewer/listener belongs is obtained (3); data characterizing viewers/listeners group targeted by each piece of advertisement data is received and associated with the piece of advertisement data (3); for each registered viewer/listener, based on a degree of coincidence between the data characterizing the group to which the viewer/listener belongs and the data characterizing the viewers/listeners group targeted by each piece of advertisement data, selecting from the pieces of advertisement data one or more pieces of advertisement data which will be transmitted to the receiver of the viewer/listener, and assigning the selected pieces of advertisement data to the viewer/listener (6); and, to each registered viewer/listener, transmitting the one or more pieces of advertisement data assigned to the viewer/listener to the receiver (20) of the viewer/listener.