I heard this in a presentation some time ago and believe it was credited to Louis Gerstner of IBM fame.  I think it is a great quote and one worthy of remembering. 

Regardless of your job or role, what you measure and how you hold those accountable to what you measure will influence their behavior.  The important thing to do is to make sure the metrics and measures you are using are the right ones.  Number of calls made, site traffic, expenses, time in the office, leads generated, proposals sent, amount of time to follow up on a lead, etc. will influence how people work and what they prioritize. 

Be sure to inspect but make sure you inspect the right things.