Pros
The other employees and most of the customers are really nice. I enjoyed the people I worked with very much. There are always new kids coming in as cashiers, and there are a lot of opportunities for promotion if you do a good job and will be working there for a while. I saw people go from cashier to self-checkout supervisor to customer service desk over the course of a few months. Also, I was able to get days off very easily when I asked for them.
Cons
I tended to get more hours than I wanted, and always long shifts on Saturdays and Sundays which was a bummer because I couldn't go to church. And schedules come out on Fridays for the following week; I only knew my hours for Sundays two days in advance. My schedule was never consistent from week to week, making planning things with friends/school/etc ahead of time (unless there were a few weeks in which I could request a particular day/time of day off) impossible. My boss was nice, but a little scary when she was stressed, and always busy doing one thing or another. I was a shy high school student, and couldn't muster up the courage to talk to her if there was something I needed, like less hours. (Most of the time, though, she was very accommodating to me.)