everything you ever wanted to know about oligopolies . . .
http://oligopolywatch.com/"Oligopolies have been around as long as commerce has. The term denotes a situation where there are few sellers for a product or service. The members of an oligopoly change the nature of a free market. While they can't dictate price and availability like a monopoly can, they often turn into friendly competitors, since it is in all the members' interest to maintain a stable market and profitable prices.
"The new oligopoly is made up of multinational corporations that have chosen specific product or service categories to dominate. In each category, over time, only two to four major players prosper. Starting a new company in that market segment is difficult, and the few that do succeed are often gobbled up or run out of business by the oligopolies.
"Few multinationals aspire to be monopolies. Monopolies attract government regulation and consumer anger (just ask Microsoft). Small oligopolies (such as Coke, Pepsi, and Cadbury-Schweppes) make plenty of money and avoid the constant attention of the regulators."
http://oligopolywatch.com/