Answer:
Substantiality.
Explanation:
Market segmentation is one of the important marketing strategies to divide the entire market into small segments in order to implement a better technique to satisfy the consumer need with specific products and schemes. There are four basic criteria for useful segmentation of the market:
Substantiality: This criterion of segmentation express the notion that the target market must be large enough to be profitable as a small segment can not justify the investment.
Similarly in the given case, it talks about the substantiality criteria of segmentation as it says a selected segment must be large enough to warrant developing and maintaining a special marketing mix.
