It can be argued that much consumer dissatisfaction with marketing strategies arises from

an inability to aim advertising at only the likely buyers of a given product. There are three groups of consumers who are affected by the marketing process. First, there is the market segment-people who need the commodity in question. Second, there is the program target-people in the market segment with the "best fit" characteristics for a specific product. Lots of people may need trousers, but only a few qualify as likely buyers of very expensive designer trousers. Finally, there is the program audience all people who are actually exposed to the marketing program without regard to whether they need or want the product.

These three groups are rarely identical. An exception occurs occasionally in cases where customers for a particular industrial product may be few and easily identifiable. Such customers, all sharing a particular need, are likely to form. a meaningful target, for example, all companies with a particular application of the product in question, such as high-speed fillers of bottles at breweries. In such circumstances, direct selling (marketing that reaches only the program target) is likely to be economically justified, and highly specialized trade media exist to expose members of the program target--and only members of the program target--to the marketing program.

Most consumer-goods markets are significantly different. Typically, there are many rather than few potential customers. Each represents a relatively small percentage of potential sales. Rarely do members of a particular market segment group themselves neatly into a meaningful program target. There are substantial differences among consumers with similar demographic characteristics. Even with all the past decade's advances in information technology, direct selling of consumer goods is rare, and mass marketing--a marketing approach that aims at a wide audience--remains the only economically feasible mode. Unfortunately, there are few media that allow the marketer to direct a marketing program exclusively to the program target. Inevitably, people get exposed to a great deal of marketing for products in which they have no interest and so they become annoyed.

The author implies which of the following about specialized trade media？

A．They can be used only when direct selling is not economically feasible.

B．They are used only for very expensive products.

C．They are rarely used in marketing programs for industrial products.

D．They are used only when direct selling has not reached the appropriate segment.