Cost of Attrition
Doesn't mention the benefits of attrition. A network can be robust since none of the pieces leaves, but what is even more robust is a network that constantly renews itself and gracefully handles the process of swapping out parts. Constant attrition means that your company never starts relying on individuals, instead the process survives and thrives on its own, hiring new people who then hire new people before they leave etc. Such a process isn't very attractive to individuals, of course, but they are very attractive to the owners.