Pros
you meet new people every day. you learn about style and therefore get a good sense for fashion. You learn how to dress and be versatile with your wardrobe. The people you work with, at least in my store, are always in a good mood and willing to help out. Its also good to receive compliments when customers like the outfit that you are wearing. It makes you feel good, and it makes them think about possibly getting that item for themselves as well.
Cons
When it gets busy, it GETS BUSY. but that's just part of the business. Sometimes customers might think they are royalty, but you learn to deal with that type. Overall, the only con I can think of is closing time when people in the store come in, make a mess, and don't buy anything. They make you clean up their mess. Then again, that's what you're getting paid to do.