The fish rots from the head. When a staff member leaves, you give him the training and experience he has obtained and your company's name on his curriculum vitae. There is a lot more movement in the market, so from an employer's point of view, if you are able to delay the employee's leaving for a year, it is a success. The challenge is to define what is a healthy staff turnover, what is a mutually beneficial period of employment. A company is a living organism.
People are a company's lifeblood.