One of the most important things companies can do for their organizational health and well-being is to hire entry-level people with an eye towards the future and design career paths and developmental opportunities for them.
The longevity of the company depends on it. Cultivating star performers on your team so that they grow into superior performers means that when leadership positions open up, they are ready and eager to step into them. The benefits of this can't be overstated. The organization can promote internal candidates who have been specifically developed for a position. That, in turn, allows others to be promoted.
Internal candidates who are dug into the company and its culture generally learn faster and become integrated into those positions more easily than candidates hired from outside the company. The time it takes to be highly effective in a leadership role is shorter for the employee already acclimated to the company's culture, strategic planning process, and budgeting systems. Promoting from within saves a great deal of time and money in recruiting and training.