Most Americans have at least one credit card. They give their owners automatic credit in stores, restaurants, and hotels, at home, across the country, and even abroad. And they also make many banking services available. For many of us the "cashless society" is already here.
While computers offer these conveniences to consumers, they have many advantages for sellers too. Electronic cash registers can do much more than simply ring up sales. They can keep a wide range of records, including who sold what, when, and to whom. This information allows businessmen to keep track of their list of goods by showing which items are being sold and how fast they are moving. Decisions to reorder or return goods to suppliers can then be made.
At the same time these computers record which hours are busiest and which employees are the most efficient, allowing personnel and staffing assignments to be made accordingly. And they also identify preferred customers for promotional campaigns. Computers are relied on by manufacturers for similar reasons. Computer-aided marketing reports can help to decide which products to emphasize now, which to develop for the future, and which to drop. Computers keep track of goods in stock, of raw materials on hand, and even of the production process itself.
Numerous other commercial enterprises, from theaters to magazine publishers, from gas and electric utilities to milk processors, bring better and more efficient services to consumers through the use of computers.

This passage is mainly about ______.

A. approaches to the commercial use of computers
B. conveniences brought about by computers in business
C. significance of automation in commercial enterprises
D. advantages of credit cards in business

请简述与顾客沟通管理的渠道和方式。