Unlike public media, private media is distinctly for profit.   Private media is sustained by commercial revenue.  Corporate media is simply private mass media that is controlled by a corporation as opposed to individuals.  For example, while in the 1980s roughly 50 different corporations controlled the vast majority of private media in the US, in 2012 this had consolidated to six mega corporations: Time Warner, Walt Disney, NBC Universal, CBS Corporation, Viacom, and Rupert Murdoch’s News Corp.  Another company, Clear Channel owned over 1000 radio stations.

Private and corporate media cover the spectrum of media types:

Private broadcasters range from giant multinational corporations run by some of the richest and most politically powerful people in the world to small, local FM stations. In most cases, broadcasting will be under the terms of a license granted on a periodic basis by a public authority. How prescriptive or restrictive are the terms of that license will also vary, often laying down certain terms under which news or current affairs can be broadcast. Sometimes this will include prescriptions as to what election coverage should be carried. There may also be an explicit public service component to the license - for example, obliging the licensee to carry voter education programmes.

Private print media is also extremely diverse, ranging from daily to weekly newspapers and magazines, to special-interest publications and journals, relying on advertising and sales for revenue. Even in situations where the state retains a large stake in broadcasting, the print media are usually in private hands. Even in authoritarian contexts, at least some newspapers in any country are likely to conduct serious news investigations and to comment in a reasonably sophisticated manner on political developments.

But private newspapers often still have their own political agendas, which may not necessarily be a democratic one. A notorious example was the Chilean newspaper El Mercurio, which, aided by the CIA, campaigned against the elected government in 1973 and in favour of a military coup - a clear case where the press dismally failed to promote political pluralism.

Even in mature democracies, newspapers are perhaps more likely than broadcasting stations to endorse a political candidate or party explicitly, although political culture varies from country to country. In many countries explicit editorial endorsement of a political choice would be unthinkable; in others it is regarded as normal. Journalistic ethics would still demand that news reportage of fact be strictly separated from the expression of editorial comment. Nevertheless, a chosen political agenda will almost inevitably affect the selection of which news is to be covered. The usual argument, however, is that the existence of a variety of newspapers reflecting different viewpoints will ensure a better-informed public and a free interplay of political ideas.

Media convergence means that the concepts of separate print, broadcast and online media are starting to become obsolete. Many outlets which were traditionally one thing or another are now operating across a range of mediums.

Corporate media is big business. The past half-century has witnessed the expansion of large media conglomerates owning a wide range of media as well as other business interests (and of non-media conglomerates buying into the media industry). The result of these developments has been a media landscape that is often far removed from the ideal of the neutral “fourth estate” – press that are independent and detached from the political process. The media owners have a partisan interest in the political process in the same way that any company will have. Thus in a sense the line between private, or (supposedly) independent media, and state-owned media is blurred.