The retail sector -- which includes all types of stores that sell goods directly to consumers -- has been through some major upheaval over the past few years. The internet, specifically (but not only), Amazon (NASDAQ: AMZN), has changed consumer behavior and led to what many have called the "retail apocalypse."Whether or not you agree with the theory of a "retail apocalypse," it's tough to argue that the emergence of the internet didn't create a retail shakeout.