I have to agree with Phemonix, the idea that we can predict when each employee will quit from information like this is ludicrous. The fact that they expect us to believe this crap, is the same as predicting when someone is going to die based on the family's previous life expectancies. All they're doing is deluding themselves like Enron did. What Enron did was using previous years of accounting (falsified and contorted to appear profitable) to predict a false profitable future, which they submitted to the public and basically screwed America and it's citizens.
I admit the fact that there is more information to work with thanks to facebook and twitter. However that does not mean that we as humans have become easier to predict. It is true that some people are creatures of habit (some have OCD, excetera), we as a species are chaotic and unpredictable. We can predict a basic idea of what a person can do, but it is not a perfect science, maybe 30% accurate if I'm generous.