A computer network chat room system includes plural chat rooms, with the conversation in each chat room being related to the program being broadcast real-time over a respective TV or radio channel in a user-defined time zone. Computer users access the chat rooms via the Internet by inputting their desired television or radio channel, along with a request to enter a chat room. A chat window is presented to the users of the system, along with a Web page window relating to the program currently being broadcast over the respective channel, and two advertising windows that also relate to the current program that is the discussion topic of the respective chat room. Additionally, a merchandising window can be presented for effecting transactions of merchandise that relates to the current program. A time zone-dependent channel guide is also advantageously provided to the computer users.