A. It is used in the marketing of most industrial products.
B. It is often used in cases where there is a large program target.
C. It is not economically feasible for most marketing programs.
D. It is used only for products for which there are many potential customers.

A. Put the homework on Don’s desk.
B. Leave the master key for Don.
C. Give Don’s students the next assignment.
D. Call Don at the end of the afternoon.