(4) In the right market or field of service.

_Your_ success will be in direct proportion to your thorough knowledge
and continual use of _all four parts_ of the whole secret. No matter how
great your effort, an entire lack of one or more of these principal
elements of Certain Success will cause partial or utter failure in your
life ambition. You will be like a man who tries to open a safe with a
four-combination lock, though he knows only two or three of the numbers.

No one, however well fitted for success elsewhere, can succeed in the
_wrong field_, or in rendering services for which _he_ is not qualified.
Nor is complete success attainable by a man unless he develops the
_best_ that is in him. Even if he brings to the right market his utmost
ability, he may fail miserably by making a _false impression_ that he
is unfitted for the opportunity he wants. Or he may be overlooked
because he does not make the _true_ impression of his fitness.

Evidently, in order to gain a _chance_ to succeed, anyone must first
_sell_ to the fullest advantage the idea that he is _the_ man for the
opportunity already waiting or for the new opening he makes for himself.
Of course he cannot do this _surely_ unless he _knows how_. Therefore
sales knowledge is _universally needed_ to complement the three other
principal elements of the complete secret of certain success.

[Sidenote: Reasons for Failures]

When we try to explain the failure of any man who seems worthy to have
succeeded, we nearly always say, in substance, one of three things about
his case: