Pros
They'll always need you, so if you want the hours, they'll give them to you. If you don't like your coworker, wait a week - turn over is super quick. Good for if you need a job while looking for something that will treat you like a human being instead of a warm body.
Cons
You will never get time off. You will never earn enough money to put up with the customers or the demands of upper management, to make it worth feeling like all your work is worth less than the dirt on their shoes. I worked for 7 different managers in my time, and an in-store manager can be good to you, can work with you. Any higher posted manager sees you as less than human. They can replace you for beans. Not worth giving your time, long term. You will never receive enough training; they will have you work alone after a single training shift.