A generator acquires, from an index information storage unit, a group identifier and commodity identifiers stored in association with the group identifier. The generator also acquires commodity information associated with the commodity identifiers acquired from the index information storage unit, from an all PLU information storage units. The generator generates group-specific PLU information which associates the commodity identifiers acquired from the index information storage unit with the commodity information associated with the commodity identifiers and that is acquired from the all PLU information storage unit. A transmitter sends the group-specific PLU information generated by the generator to terminals belonging to a group that is identified by the group identifier corresponding to the group-specific PLU information.