segmentation: identify customer groups of 1. similar needs for specific product benefit 2.similar purchasing behavior and response to 4Ps

a segment has to be:

1. identifiable            2.accessible                 3.predictive of future profits

selective demand : when company deliver message about how their brand or product is the best match for the needs of the target market

heavy half theory: half consumers account for 80% consumption

descriptive approach:  geographics, demographics, socio-enomomic characteristics....

behavioral approach:  characteristics that are directly relevant to marketers

example: 

1. benefits sought

2. attitudes towards products

3. likelihood of purchase

4. price sensitivity

5. purchase volume

6. loyalty--retention rate

7. customer life-time value

8. media response 

9. need for service

behavioral approach profiles into descriptive approach