To reduce cost for a system change and allow a terminal of one model to perform purchase plan registration of content for a terminal of another model.
An online store cooperation system 1 includes: user terminals 21 and 31 of which models are different; a front server 22 for performing sales of digital content (hereinafter called commodity) to the user terminal 21 through a communication network 50a; a front server 32 for performing sales of a commodity to the user terminal 31 through a communication network 50e; and a purchase plan list server 40 that is connected to the front servers 22 and 32 through communication networks 50c and 50g and has a purchase plan list. The front server 22 registers a commodity selected by operation of the user terminal 21 in the purchase plan list. The front server 32 performs purchase processing of a commodity selected from the purchase plan list by operation of the user terminal 32.
NISHIKAWA HITOSHI
TOSHIMA AKIRA