The process of receiving orders and shipping and tracking goods sold through direct marketing is called fulfillment. Common sense suggests that every company cannot produce or market products to suit every person, purpose and purse in the market place. People may differ in their buying motives, in the features and benefits they seek from a product and in their buying habits. People living in different places may vary in their buying of the same product. In pricing too, consumers differ in what they can afford and what they would like to spend on specific product categories.

A mental listing of the various 'popular' or lower priced brands versus the 'premium' or high priced brands of the same product category would speak volumes about differing price expectations of consumers. Hence, to fulfill the need of a customer, companies have to take a decision that whether to make a product, which suits everybody, or to make various products to suit various customer groups or to make a unique product for every customer. While it is possible to follow any of the three approaches, the cost and the other marketing implications make it a difficult decision for the companies. Company has to also decide whether he will market his product to all users of the product category or concentrate on a group of users who exhibit similar characteristics. In other words, a company has to decide whether he will serve the entire market or a market segment.

A market segment is a large, identifiable group of customers within a market, showing a predictable pattern of behavior in buying situations, and able to be profitably reached by means of distribution and communication. In some product categories, every customer could become a segment- interior decoration, jewelry, designer wear, and industrial equipment. In these cases, it is both possible and viable to serve each customer with a unique product and a unique marketing mix.