Ventajas
Great benefits if you become full-time. Even part-time is manageable with benefits.
Not arduous work at all.
Holiday and premium pay available dependent on scheduling.
Both Annual AND Sick leave (if you use one, you still have the other and they both accumulate at the same rate. Sick leave never expires.)
Shopping privileges! (at the time of writing this)
Pension/retirement fund.
Desventajas
Management can be hit-or-miss. There are those who will jump through hoops and stick up for you. Meanwhile, there are others who would throw you to the wolves or just write you up for anything. (I thankfully have had the former but have seen it get down to the ladder)
Work-life balance can start to suck you dry if you sign up for more work than originally tasked with. Always remember, if you start one thing, you can count on doing that one thing again and again and again and again.
Moving up in promotions or pay-grades is like pulling teeth. Someone has to be removed or leave before you can get any permanent position, and most from what I heard, they will skip over you. Seniority matters.
Make sure you know which positions you are going for. Front-end is easily the worst department across the board. (People love being else where in the store)