| 摘要 |
According to the present invention, a reception unit (101) receives, from a subscriber, a new subscription request in which an unregistered message-providing source is specified. If the number of message-providing sources of messages addressed to the subscriber has not reached an upper limit number set for the subscriber, an addition unit (102) adds, as a message-providing source of messages addressed to the subscriber, the unregistered message-providing source which is specified in the new subscription request. A provision unit (103) provides the subscriber with a message from the message-providing source of messages addressed to the subscriber. An assessment unit (104) assesses a reaction of the subscriber to the provided message. If the assessed reaction satisfies a predetermined high-level reaction condition, an update unit (105) performs an update to increase the upper limit number set for the subscriber. |
