" Avinash Kaushik, author and Digital Marketing Evangelist at Google, says former US Secretary of Defense Donald Rumsfeld knew a thing or two about analytics. According to Rumsfeld: There are known knowns; there are things we know that we know. There are known unknowns; that is to say there are things that we now know we don’t know. But there are also unknown unknowns — there are things we do not know, we don’t know. "

― , Lean Analytics: Use Data to Build a Better Startup Faster