A new client of mine said, "You know, our tenure averages 15-20 years for certain jobs. When you think about it, our Hiring Managers are making $2 million dollar investment decisions when they decide to hire someone."
He was leveraging simple math - [fully loaded salary] x [years in the job] = $2 million dollar decisions.
Now, your company may only have expectations of people staying in their jobs for 5 years. But still, that could easily be a 1/2 or 3/4 million dollar decision.
Anyway, I liked the way he talked about the financial investment/decision without using the typical negative-feeling measures around costs of turnover, lost productivity, lost customers, recruiting costs, wasted training, etc.