The issue is that rigorously measuring results is hard, and frequently when people try to quantify results, they screw it up and force people to spend their time gaming a dysfunctional metric instead of doing real work.

This is a problem in business as well. Marketo is able to charge companies thousands per month for tracking online advertising outcomes in companies with long, relationship-based B2B sales cycles (who might be aiming to make a few huge sales per year).

John Wanamaker: "Half the money I spend on advertising is wasted; the trouble is I don't know which half."