1. A client device configured to receive at least one targeted message from a server in communication with the client device, the client device comprising: a voice recognition unit configured to convert at least one term in voice data into text data; a data transmission unit configured to transmit communication data to a server, wherein the communication data includes the text data generated by the voice recognition unit; a message reception unit configured to: receive a targeted message from the server, wherein the targeted message is selected by the server from a server database comprising a plurality of messages, in accordance with user profile information that is generated by the server based on the communication data; and an output unit configured to provide the targeted message, received by the message reception unit, to a user of the client device.