Unless it's a specialized storefront that sells ecig products, i've found that they're entirely clueless, especially when dealing with the gas station/tobacco store brands. Overall they seemed to somewhat interested tho and asked me how i liked them (this was back when i was trying out disposables and different mini models)
The mall sellers on the other hand, are worse than clueless. Not only do they possess no knowledge about the products whatsoever, but they've been given a list of 15 pre-designated responses as to why their ****ty product is the best and their ****ty price is fair. They exist for no other purpose than to screw over new vapers. They don't even know the mAh of their batteries or ohms of their atomizers, they don't know if their juice is PG or VG, or specifically what nic their juice is (them: there's high medium and low; me: but how much actual mg/ml is that? them: what?)
So to summarize, unless you have a big ecig specialized storefront near you, we're all probably better off sticking to the internet