Do your decisions make money?

I am reading a book by Eric Reis right now called The Lean Startup, and the most recent chapter I came to was on "innovative accounting". It was encouraging in one sense because I think we practice a lot of what he talks about. But then it got me thinking about all the data we DO NOT track. Do you track data in your business? If so, how do you decide if the data is worth tracking? Here are my humble thoughts on when to track data: 1. Can you measure it successfully and faithfully? If you try to track an impossible number you will get discouraged and give up. 2. Is it something that can change your business? If you can't do anything about it, why track it? Which leads me to my final point. 3. Is it actionable? Can you react to the data? If so, how are you reacting? This should be information that affects change in your business. How do you know when something is worth tracking? How do you track your data?