A cluster extractor extracts a plurality of clusters based on communication records between communication terminals. A clustering coefficient calculator, an average path length calculator, and a degree distribution calculator calculate a clustering coefficient, an average path length in an advertisement distribution target cluster, and a degree distribution, respectively, based on communication records between communication terminals belonging to an advertisement distribution target cluster. An advertising strategy determiner determines an advertising strategy, based on the clustering coefficient and the average path length, and a distribution target determiner determines a distribution target terminal, based on the degree distribution and the advertising strategy. A determined target notifier notifies a communication management device of the distribution target terminal and the advertising strategy and an advertisement distributor distributes an advertisement according to the advertising strategy to the distribution target communication terminal.