A home storage (a first storage device) installed in each home is provided with an area for a user to store data (user area) and an area for storing ads (ad area). The first storage device checks interest and favorite information for the user in the user area, and transmits the interest and favorite information at the same time backup is performed in a second storage device at a remote site. The second storage device selects a suitable ad based on the interest and favorite information from the first storage device and transmits the selected ad to the first storage device. The user views the transmitted ad when viewing content in the first storage device. The user's viewing record for the ads is kept as statistical data, and the second storage device compiles the record, charges a sponsor an ad charge, thereby subsidizing the usage charge for the first storage device regardless of online or offline connection.