I actually had the opposite experience as Brad H (see his review on 7/10/08). I want to compliment two of the cashiers/regular workers and one of the managers.
I wanted to buy a cat tower but I noticed that one of them had fur on it already! And you know how territorial cats are, my cat probably wouldn't want anything to do with it if it had already been scented. So I asked a nice young gal about how they sold them and if we are supposed to carry off what's displayed or if they are in the back somewhere in boxes. She said whatever is out on the floor is all they have usually unless they have a couple extras in the very top shelves. She offered to call her manager for me and I accepted.
The manager came immediately and was helpful and friendly. She offered to give me a discount on the one that had fur on it and she also went to see if there were extras in those top-shelf areas. There were, but I felt bad (and didn't have much time) making her get someone with a forklift to get it down and go through all that trouble. Anyway, I ended up getting a different one that had no trace of "being tested out" -- which isn't actually allowed, so someone must have snuck their animal onto that other one or something. She helped me carry mine to the register.
Then to top it off, the cashier helped me not only carry it out to my car, but spent like 5 minutes out there in the AZ heat with me as we figured out how to fit the darn thing in my car! She was friendly and happy to help the whole time.
Overall I am really satisfied with my time spent there and even though all Petsmarts have pretty expensive items, their people make it worth the experience.