Abstract: A program content tagging system for facilitating the development of an interactive social network during the viewing of a program comprising a base station, a database, an output device, and an input device. The base station serves as the conduit for bidirectional communication between the user and the output device. The database stores a library of program content and/or other program content identification to provide a means for identifying the program content transmitted to the user. The output device allows the user to view any additional information synchronized with the program content. The input device allows the user to request or send information to the base station for processing. The user may activate a tag mark displayed on the output device to view additional information. With this information users, vendors, and visitors can engage in commerce through the use of advertisements and sales of goods and services.