Dear Marty cagan Root cause to FAILURE of any product and service is only two 1.Product and Service without any requirement or demand example: lot of gadget, music, game, technology FAILURE due to no customer no requirement no demand 2.Product and services FAILURE due to customer INCAPABLE to meet consideration. example: In Chennai only UDHAYANIDHI MKSTALIN KALANITHIMARAN KANIMOZHI DHAYANIDHIALAGIRI Network Element friend and family only has MONEY rest of people don't have MONEY as result in Chennai World famous BIKE failure, LUXURY car failure, LUXURY hotels air ticket failure and Chennai Population is 500Million but 250Million Sq.Ft vacant and ideal like China GHOST town these two are root cause to FAILURE of any product and service