What is the Iceberg Effect?

It may be explained with the help of an e.g.:

Take a salesman of a wide line of sporting goods. His job is to sell to sporting goods shops, hardware stores, and department stores.  His experience, prior to taking this present job, has been in hardware merchandising, and, as a consequence, he favours selling to this group. This man’s selling record was good. However, his manager noticed that a preponderance of his orders came from hardware stores, although this, he felt was not the pattern of the other salesmen in his orders came from hardware stores, although this, he felt, was not ht pattern of the other salesman in his group. Sa he decided to analyze the man’s sales by types of account- something he had never bothered to do before. He also made a similar study of the five other salesmen in his group. The six-month record looked like this.

The ‘iceberg’ (total sales) showed that salesman “A” was actually over quota, but the detailed analysis indicated that the man might not be realizing the potential his territory as far as supporting goods stores and department stores well organized. It may be that, having got a complete view of the ‘iceberg’, the manager will want to make some of his effort to get this man to sell to the other outlets with the same enthusiasm he shows for hardware outlets. At least, he is a position to exercise more precise control over the salesman’s activities than was before he made his analysis. In addition, he may have at the same time discovered that his other five salesmen could generate sales from hardware outlet if they reallocated their efforts somewhat.