Disclosed is a method of measuring audience ratings for at least more than one service and content in a terminal. The measurement method may include receiving a campaign invitation message for an audience measurement campaign from a server. The campaign invitation message may include at least more than one of information for the audience measurement campaign, information for the server, and information for an opt-in rate of the audience measurement campaign. The method may further include authenticating the information for the server in the campaign invitation message. The method may further include determining whether to participate using the information for the opt-in rate of the audience measurement campaign in the campaign invitation message. The method may further include transmitting a panel opt-in request message to the server according to the determination result. The method may further include receiving a panel opt-in response message from the server.