Even a century ago, the number of media with any substantial outreach was limited by the large size of the necessary investment, and this limitation has become increasingly effective over time. As in any well developed market, this means that there are very effective natural barriers to entry into the media industry. Due to this process of concentration, the ownership of the major media has become increasingly concentrated in fewer and fewer hands. As Ben Bagdikian's stresses in his book Media Monopoly, the 29 largest media systems account for over half of the output of all newspapers, and most of the sales and audiences in magazines, broadcasting, books, and movies. The "top tier" of these — somewhere between 10 and 24 systems — along with the government and wire services, "defines the news agenda and supplies much of the national and international news to the lower tiers of the media, and thus for the general public" [Ibid., p. 5]

The twenty-four top-tier companies are large, profit-seeking corporations, owned and controlled by very wealthy people. Many of these companies are fully integrated into the financial market, with the result that the pressures of stockholders, directors, and bankers to focus on the bottom line are powerful. These pressures have intensified in recent years as media stocks have become market favourites and as deregulation has increased profitability and so the threat of take-overs.

The media giants have also diversified into other fields. For example GE, and Westinghouse, both owners of major television networks, are huge, diversified multinational companies heavily involved in the controversial areas of weapons production and nuclear power. GE and Westinghouse depend on the government to subsidise their nuclear power and military research and development, and to create a favourable climate for their overseas sales and investments. Similar dependence on the government affect other media.

Because they are large corporations with international investment interests, the major media tend to have a right-wing political bias. In addition, members of the business class own most of the mass media, the bulk of which depends for their existence on advertising revenue (which in turn comes from private business). Business also provides a substantial share of "experts" for news programmes and generates massive "flak." Claims that they are "left-leaning" are sheer disinformation manufactured by the "flak" organisations described below.

Thus Herman and Chomsky:

"the dominant media forms are quite large businesses; they are controlled by very wealthy people or by managers who are subject to sharp constraints by owners and other market-profit-oriented forces; and they are closely interlocked, and have important common interests, with other major corporations, banks, and government. This is the first powerful filter that effects news choices." [Ibid., p. 14]

Needless to say, reporters and editors will be selected based upon how well their work reflects the interests and needs of their employers. Thus a radical reporter and a more mainstream one both of the same skills and abilities would have very different careers within the industry. Unless the radical reporter toned down their copy, they are unlikely to see it printed unedited or unchanged. Thus the structure within the media firm will tend to penalise radical viewpoints, encouraging an acceptance of the status quo in order to further a career. This selection process ensures that owners do not need to order editors or reporters what to do — to be successful they will have to internalise the values of their employers.