One of the criteria for a usable market segment is its size. This chapter suggested that to be usable, a segment must be large enough to be profitable now and in the future and that some very small segments get ignored because they can never be profitable. So how large should a segment be?

How do you think a firm should go about determining if a segment is profitable?

Have technological advances made it possible for smaller segments to be profitable? Do firms ever have a moral or ethical obligation to develop products for small, unprofitable segments? When?