Pros
A heavy focus on Customer Service helps train you for the sales field, and if you work at the right one, they really get it right on with how to train someone to help the general public. You can easily pick up this skill within about a year here.
Cons
Training usually consists of teaching you how to give customer service, teaching you how to follow safety procedures, and then throwing you in a department without training the working skills of the department. I've worked seven different positions, and I've only received full training for two of them. The other five were partially or completely self-taught. Bakery in particular had little to no training, is constantly understaffed due to a lack of putting people behind the counter, and receives a heavy work load due to the fact that they create 90% of the product on their shelves themselves. The other major problem is the contract gap. The strike was resolved by giving any new hires the contract that was worse for the employees. While it doesn't really cause friction between employees, the only real way you can make a living, or even full time, is to enter a supervisory or management position. Outside of that, you can expect to have fewer hours in a company that pushes you to avoid full time like the plague.