What are mass media primarily used for?

Mass media primarily serve the function of conveying messages to large audiences. This is a fundamental characteristic of mass media, which includes television, radio, newspapers, and the internet, among other forms. The essence of mass media lies in its ability to reach a broad spectrum of the population simultaneously, making information accessible to many people across diverse geographical locations.

Mass media play a crucial role in shaping public opinion, disseminating news, sharing entertainment, and providing education to the masses. By targeting large audiences, it can influence societal norms and values, mobilize public discourse, and foster cultural exchange on a scale that smaller forms of communication cannot achieve.

In contrast, the other options point towards functions that do not align with the primary purpose of mass media. Restricting communication to small groups is contrary to the concept of "mass," as it inherently involves reaching the public at large. Promoting local cultures only limits the broader scope of mass media, which can transcend local boundaries and have a global impact. Finally, the provision of in-depth academic research is usually the domain of specialized publications rather than mass media, which tends to focus on more general content suitable for a wide audience.