Nike Never Test Work, Is It Driven by Client and Agency Instinct?

Do you test your work at all? Is there any sort of activity that sort of tests the work before it goes in market? Or again, is it more driven by client and agency instinct? And then how do you know if it's working? So, Nike never test work. The reason they never have and they probably never will and they certainly don't now is because it goes way back to the origins of kind of the advertising in some senses on Nike.