To provide a mail-order sale method and system, a receiver and a memory card with which catalog information stored on a recording medium can be updated by utilizing data broadcasting and communication time and communication cost can be reduced.

The recording medium 3 where an identifier capable of discriminating a broadcasting station 1 or its broadcasting program is recorded and merchandise catalog information is stored is prepared, and the catalog information of the medium 3 is updated with data transmitted by the data broadcasting of the station 1. The receiver 2 displays the catalog information written on the medium 3 on the display, and a user can select merchandise while interactively operating on the screen and transmit ordering data at an order receiving server through a line. As the recording medium 3, the memory card that is small in size and light in weight despite of being mass in capacity is used.