The first thing you do every day at PetSmart is dump the dead reptiles into the trash. We treated them as well as we could once they were in the store — given our fairly minimal resources — but they're mistreated in transit and often die within a day of arriving at the store. We once reordered a chameleon three times because they kept dying. Everyone knew they were too delicate to transport, but head office wanted a chameleon in the store. Most employees aren't aware of this, since management tries to sweep it under the rug, but I was the morning custodian.
The birds are also neurotic as hell due to sheer mind-numbing boredom, and the rodents bite because they're unsocialized. Elderly hamsters get put in the back room, where they'll never be purchased, because they make customers sad. At least in my experience, the employees genuinely try to take care of the animals, but it's just not a good environment for them.
The cats are okay, though, since they're not actually sold by PetSmart. The company just rents out display space to rescue groups and shelters. They're mostly pretty happy and well cared for.