A relay device is provided that is provided on a first network hierarchy level and relays communications via a network hierarchy level higher than the first level, between a plurality of nodes subordinate to the relay device and a sales broker website, and includes: an application storage unit storing a sales broker application; and an application execution unit executing the sales broker application to cause the relay device to function as: an order data reception unit receiving order data including a plurality of contents; a first order data transmission unit transmitting the order data to the sales broker website; and a second order data transmission unit transmitting, when an order receiver node receiving an order for the product is any of the plurality of nodes, at least a part of the plurality of contents to the order receiver node without involving a level higher than the first level.