very little has been saved in the overall cycle. This question is some- times complicated by multiple use of transmitted data. Sales data from a branch office can be used to generate shipping orders, in- voices, inventory replenishments and sales analyses, each with a dif- ferent time priority. This leads to a second consideration-extent of data collected. In the example just cited, extra information is required for each in- tended usage. And each little bit adds to the transmission time, the processing time, etc.-all the way down the line. This is not to say that the additional uses should be eliminated and only the bare bones transmitted. After all, the incremental cost to handle a little bit more is usually small in comparison to the total cost of the system. But even a small incremental cost compounded many times can add up to a sizable cost once in motion. 1.4.2 Minimizing Line Costs As the size and volume of the transmitted messages grow, a closer look is taken at the communications lines connecting the terminals with the computer. Because the cost of the communications lines can easily amount to one-third of the cost of the whole system, econ- omies here can have important budgetary effects. Several techniques are available to reduce the line costs and per- haps improve performance at the same time. A private line can be THE MEDIUM AND THE MARKET leased from the telephone company, giving exclusive use to the cus- tomer for 24 hours a day. If the volume from one location is insuf- ficient to warrant a private line, perhaps several locations can share the same line in a multi-drop fashion. This requires that the terminals be equipped to recognize their own addresses, so that information directed to one terminal won't be sent to all the other terminals. It also introduces the problem of multiple stations competing for use of the one line. With the dial-up telephone network, the telephone company equipment takes care of this problem for you automati- cally. Another capability that is achievable on a multi-drop