Even if I don't agree with it, I still try to treat everyone with respect.
I work in customer service, too! The only times I go out of my way to put someone down is if they're being rowdy or violent toward anyone, or when they hype up overpriced products that I think are awful and don't want people to stress themselves to get it (I don't work commission, but I am working on that part though. I acknowledge some people actually will like them, but I just don't want anyone following hype for something they won't enjoy.)