Pros
I worked at one of the retails during my college years, not as a sales clerk but as a concierge type of job. Although a part-time worker, I was treated in the same way as any other full-time colleagues. Im confident to say that I've learned a lot about its culture, fashion, and most importantly how to treat customers in most respectable/luxurious way. It definitely is not something that you can learn from working at a cafe/restaurant. People expect you to behave like an employee at a top-notch hotel in the world. People that I worked with were quite amazing. Not like any other luxury fashion retails, they were quite laid-back and not pretentious at all.
Cons
You can't really expect internal promotions if you are a part-time or contract at a retail. Also, there is a big gap between retail work and corporate work. I've seen some jumped to the corporate position from the retail but that rarely happens as far as I know.