If business is now a global affair, then the export-import business is important, lucrative and necessary. An export-import agent is not a broker --- the agents are lower on the business totem pole.
Most properties are measured using a number and a unit of measurement. The unit of measurement is a standard amount. The number compares the property to that standard amount. This means a tree that is ten times as tall as a meter stick is 10 meters tall.
In the classical definition, which is standard throughout the physical sciences, measurement is the determination or estimation of ratios of quantities. Quantity and measurement are mutually defined: quantitative attributes are those possible to measure, at least in principle.