With disparities in wealth greater than at any time since the Gilded Age, the gap is widening between the highly affluent and everyone else - a degree of economic and social stratification unseen in America since the days of the rigidly separated classes on the Titanic a century ago. What is different today, though, is that companies have become much more adept at identifying their top customers and knowing which psychological buttons to push. The goal is to create extravagance and exclusivity for the select few, even if it stirs up resentment elsewhere. Research has shown, a little envy can be good for the bottom line. Behind a locked door aboard Norwegian Cruise Line’s newest ship is a world most of the vessel’s 4,200 passengers will never see. And that is exactly the point.