Efficient communication may or may not be effective, but its hallmark is its brevity ( concise and exact use of words). It must be time limited, crisp and pointed. It gets the message out in the shortest time. Sometimes the message is well received; other times the brevity may be insufficient for understanding or to compel action. Sometimes the less said the better, but often a short message leaves questions unanswered and without explanation, thus the response could range from positive to negative to none at all. Efficient communication is most likely to be effective if there is pre-established, mutual understanding between the message maker and the receiver.
Effective commucication may not be brief. For communication to be effective, it has to consider the receiver. Effective communication is two-way. Effective interpersonal communication includes a lot of verification and validation. This has two purposes: One, that what was said is mutually understood, and two, that the speaker feels understood so is more likely to act.
In a sales context, effective communication is essential for attracting a customer. The potential customer must feel the product and service will address his needs in order to buy. The customer must understand the terms of the sale to be a satisfied customer. If there is a problem after the sale, effective communication facilitates the problem being solved to the customer’s satisfaction, creating customer loyalty.