Mainstream media (MSM) is a term and abbreviation used to refer collectively to the various large mass news media that influence a large number of people, and both reflect and shape prevailing currents of thought. The term is used to contrast with alternative media which may contain content with more dissenting thought at variance with the prevailing views of mainstream sources.
The term is often used for large news conglomerates, including newspapers and broadcast media, that underwent successive mergers in many countries. The concentration of media ownership has raised concerns of a homogenization of viewpoints presented to news consumers. Consequently, the term mainstream media has been widely used in conversation and the blogosphere, often in oppositional, pejorative, or dismissive senses, in discussion of the mass media and media bias.
According to philosopher Noam Chomsky, media organizations with an elite audience such as CBS News and The New York Times are successful corporations with the assets necessary to set the tone for other smaller news organizations which lack comparable resources by creating conversations that cascade down to smaller news organizations using the Associated Press and other means of aggregation. An elite mainstream sets the agenda and smaller organizations parrot it.