Final answer:
The market is considered measurable when the size, purchasing power, and profile of a market segment can be determined, which is essential for a business to target a specific market effectively.
Step-by-step explanation:
When the size, purchasing power, and profile of a market segment can be calculated, the market is measurable. In order for a market segment to be viable, it must be measurable, substantial, accessible, differentiable, and actionable. These criteria allow businesses to evaluate the potential success of targeting a specific segment. For example, a well-respected brand name that has been built up over many years helps in identifying and measuring the market segment catering to brand loyal customers.