Patent ID: 7971233

Claim:
A first communication device including a sending/receiving unit for sending content to and receiving content from a second communication device in a communication network including a plurality of communication devices, the first communication device comprising: an introduction information receiving unit operable to receive, from the second communication unit, content identification information for identifying the content, introducer identification information for identifying the second communication device as a sender of the content to the first communication device, and an introduction history including identification information for identifying a communication device that originally sent the content and identification information for identifying any other communication device that sent the content after being sent by the communication device that originally sent the content and before being received by the second communication device; an evaluation value calculation unit operable to calculate an evaluation value based on the introduction history as an evaluation element for evaluating a value of content senders; an evaluation value receiving unit operable to receive an evaluation value from each communication device other than the first communication device; a ranking generation unit operable to rank an evaluation value of the first communication device and the evaluation value for each communication device other than the first communication device, and generate an evaluation value ranking; and a presentation unit operable to present the evaluation value ranking and the introduction history to a user of the first communication device.