Pros
A lot of skills can be gained here, making it an ideal first job. Hired me when I was a student and gave me a lot of flexibility around my studies. Work varies a lot for sales assistants, and there are some truly great people working there.
Cons
If your job is as a member of management, say goodbye to any work/life balance! The amount of stress and pressure put on a supervisor in particular is unbelievable, as you become a figure in which constant complaints are directed towards from both sales assistants and higher management. Upper management do not appreciate those working tirelessly to achieve results, in fact your reward is to be told what you done wrong and given even more (often pointless) work. Severely understaffed, often given two other people in the shop at any given time then asked why the place wasn't tidied 100%, or why shelves are lying empty, because you're supposed to be able to do 1593639 things at once, and in my experience this was done in quite a bullying tone by my manager, who often seem to have their favourites. Very low wage considering the workload, stress, and wages given by competitors for similar roles, perhaps one of the reasons there is such an incredibly high staff turnover.