how to differentiate between original nike and duplicate nike product???

my guess is your talking about fake Nike sneakers , so yeah the quailty is going to a be a major factor , not to mention the price , then again there are places where you can buy a fake Nike Shoe for like 200+ but you will never know it until the quailty shows ...so the 2 major factors Quailty and Price

interesting.. i always wondered.. well i had an original nike that i know for sure and my brother bought one almost like mine but the male version on the tag of mine there was a nike sign... the tag which gives your size and everything.. his didnt have the sign so i assumed it was fake anyways but the real one has the nike sign in it also ont he sole behind... and jus be sure to get yur nike shooes from a nike dealer or nike outlet...