Editing Monopoly (section)

==== Relevant geographic market ====
It is necessary to define it because some goods can only be supplied within a narrow area due to technical, practical or legal reasons and this may help to indicate which undertakings impose a competitive constraint on the other undertakings in question. Since some goods are too expensive to transport where it might not be economic to sell them to distant markets in relation to their value, therefore the cost of transporting is a crucial factor here. Other factors might be legal controls which restricts an undertaking in a Member States from exporting goods or services to another.

Market definition may be difficult to measure but is important because if it is defined too narrowly, the undertaking may be more likely to be found dominant and if it is defined too broadly, the less likely that it will be found dominant.