Ok, others have already commented on PetSmart. Some Petco/Petsmart employees know their stuff- but my experience locally has been they are few and very very far between. Keep in mind, chameleons have not been in widespread trade for very long at all(as I recall, but I cant give you exact dates off the top of my head)- there is still a lot which is not known and our knowledge is changing rapidly (this is true of a lot of critters).
My point, I am not trying to tell you their advice is automatically bad, but I would consider the source very carefully and be very very skeptical. What one person thinks is "everything you need to know" might be based solely on their personal set up- which may not even apply to you. With employees of big pet stores like that- also bear in mind that they have to sell many species. I highly doubt every employee has had experience with each one. I always ask what their personal experience with a particular animal is. I had a petco guy tell me everything I needed to know about chameleons as well. This advice included telling me that an all glass enclosure (their big promo item of the week at the time incidently) was the ideal enclosure for a chameleon- advice that most people here would disagree with. I asked him what his personal experience was with chameleons- he told me he had one a while back but it only lived a few months and that Veileds do not live very long, the longest living one he had ever heard of being 9 months old. I respect this guy, but despite is apparent confidence and authority in reptiles he not a source I am willing to trust in this case. I have been completely screwed over by the advice of petstore employees before (even small specialty stores now). Just a last comment. Caring for any reptile is complicated. You are not going to be able to get all of the information you need from a 30 minutes discussion with a Petsmart employee. You really should consider getting a good book (or two), and spending a few hours on the web looking around at people's set ups. Try to find examples of successful ones and unsuccessful. I did this for months before I got my chameleon.
Now, to be fair as well, you also cannot trust everything you read on the internet as well. It all boils down to getting as much info as you can and attempting to the best of your ability to distill it down into the quality info. Personal anecdotes are great, and hey- you may have found an employee at petsmart who really knows their stuff! It happens. My point is, even if your next door neighbor is a world famous chameleon expert, still do tons of research and scrutinize all of it (which I know you are doing in coming here, I am just saying...)r
Just out of curiosity- what did they tell you?