Pay and retain good staff!
Just think how many TVs, PCs etc they could sell if only they developed a reputation for knowing what they were talking about and offering a great deal with great service, ie meeting needs/expectations!
I stopped going for anything other than a "distress purchase" because I know that the staff will:
a) not have a clue what they're talking about and I'll just become frustrated at their ineptitude
b) may have a slight clue what they're talking about but will still try and rip me off
c) not be at all interested but if there's a whiff of an extended warranty sale, may just feign it