It is interesting to note that the first Sony retail store wholly owned and operated by Sony opened in 1982 [1], way before the first Apple store in 2001 [2]. Although Sony had retail stores almost 20 years before Apple, their stores are not as popular, likely because of the lack of demand for their products.
I'd venture that Sony stores are only still around in the US out of some kind of corporate machismo. I can't imagine they're making enough money to be worth it.
Sony stores also charge retail for items you can get anywhere else below retail price. Apple typically prevents this by making margins razor thin on items, keeping the price consistent across retailers.
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1. http://en.wikipedia.org/wiki/Sony_Canada#Sony_Style
2. http://en.wikipedia.org/wiki/Apple_Store