Market segmentation helps marketers by using the resources available to them in a more efficient manner. By segmenting the market and identifying the group of people most likely to use the product that is being marketed a marketer can create a brand image that appeals to the target group.
The advertisements created for the product should be created keeping the target group in mind and the medium where they are displayed chosen accordingly. It does not serve any purpose to make everyone aware of the product if only a small group of people in the entire population is likely to use the product. Mass advertising is an inefficient use of resources and the to alternative to this is to identify the segment of people most likely to become customers and focus solely on them.
For example, though diapers are used by small children they are not bought by children. Here the target segment is women in the age group 25-35 that are most likely to have children. Advertising for diapers should be done on television channels watched by women. Advertisements of diapers in the middle of a baseball match would not serve much of a purpose and waste resources.