The first element of finance is not ability, but keeping secrets.

Every company has its secrets, and the biggest ones are often found in the world of finance. The CFO is the one who shares those secrets with the boss, which is why owners are reluctant to swap out their finance leads—they don't want more people knowing what they know. If someone has to know, it might as well be just one person. Choose one, and stick with them for the long haul.

In many small companies, the finance role is filled by the boss's wife. But when a company grows and she lacks the capability to handle the role, the position of CFO—seemingly one that manages only a handful of people—actually serves as the boss's most trusted confidant.