As a result , these companies often became the dominant ISPs in their service areas .
What was once a highly competitive ISP market became effectively a monopoly or duopoly in countries with a commercial telecommunications market , such as the United States .
As a result , these companies often became the dominant ISPs in their service areas , and what was once a highly competitive ISP market became effectively a monopoly or duopoly in countries with a commercial telecommunications market , such as the United States .