Pros
I worked a second job as a Sales Associate at IKEA on weekends. I loved the stores and the merchandise, and really enjoyed helping people understand a unique and different shopping experience. There was a 10% employee discount, free (restricted choice) lunch or dinner, free uniforms, and adequate training (but mostly self-administered via booklet). Full-time employees got various benefits including health insurance and vacation pay, as well as reimbursement for some external college coursework, but not many people received full-time hours. The store closed completely on three or four major holidays, and employees could receive time and a half pay for many minor holidays. There was lots of diversity among the staff, and generally positive employment policies. The current company president had risen to that level from Carts co-worker, so advancement was possible if you really focused on the company and worked hard to advance. Scheduling was as flexible as they could make it, although keeping a huge store open could create incentive to make you work hard to take a day off on a difficult staffing day.
Cons
Everything about day to day work was physically stressful. I'd never had trouble with my feet before, but standing or walking on concrete floors for 8 or more hours a day became harder and harder. Weekend work was much harder than weekday work, since the store was busy from opening to closing, After closing, the process of getting mislaid merchandise ("go-backs") back to its place was gruelling and frustrating. If different departments needed help, everyone was told to go help fetch carts from the parking lot or fold towels or roll up rugs or whatever -- this would leave your own department shorthanded for those who stayed, and nights after the 9pm closing could stretch out an extra three or four tiring hours. I worked for six months as a weekend Kitchen planner, which was a nightmare, since there was very little time to get the training you desperately needed to help deal with the complex computer systems and masses of local practice details that weren't covered in the official training booklets, and customers were waiting in long lines for the next employee to help them order all their cabinets.