You know, most of the retail sales people know that they don't know much about what they are selling. Most of them know at most what the sales brochure says in it. I'm in Best Buy a lot, perhaps too much, and they know me well enough that they usually ask me a few questions while I'm there.
Maybe I should work there part time for some discounts...nah.
Anyway, they may not know much, but for most of them its just a part time job to save money for school and go out on the weekends. Some of them try hard to learn about their products, and others just want to make it until close without making someone mad.