There are five criteria used for evaluating the usefulness of segmentation. According to the substantiality criterion, the market segments must be financially attractive and should be large or profitable enough to serve. It has no meaning to increase the costs by designing a different marketing mix for a segment that does not promise enough revenue for the company. A segment should be the largest possible homogeneous group worth pursuing with a tailored marketing program. It would not pay, for example, for an automobile manufacturer to develop cars especially for people whose height is greater than seven feet.