A monopoly is one of the categories of market structures. A monopoly is characterized by a dominant firm that has control over the market. There is also a pure monopoly in which there is only one firm in the market that supplies goods or services that do not have close substitutes. The barriers to entry are very high. Monopolistic firms are price markets. That is to say, the firm has enough market power to limit the output and arbitrarily increase prices. However, the optimal price and output are set by the point at which marginal cost equals marginal revenue. Additionally, a monopolistic firm can obtain excess profits. Currently, many countries in the world have regulated the markets since monopolies are categorized by the governments as something illegal. Therefore, the number of monopolists have been reduced over the years. Nevertheless, there are still some examples of virtual monopolistic firms that clearly dominate the market. Please find below some examples of monopolies in Nigeria and the world.

• Digital Satellite Television Nigeria (DStv) - This company is a broadcast satellite company that has been classified as a monopolistic firm in Nigeria. It has had control of the prices for many years. It has very high subscription rates which are frequently increased without any justification.
• Dangote Cement - This is a Nigerian company that is the largest manufacturer of cement in that country. This company also all control over the market prices and has forced to increase prices on many occasions.
• Intel - Intel is another example of a monopolist. Intel dominates the market share of PC processors in the world since it has more than 80% of the market share.
• Netflix - This media-service provider dominates all the market. The market share of Netflix is 87%. Additionally, it also has control over the prices.