The employees of those stores have very little training on the individual products they sale. I observed a Best Buy employee answer some questions about a Kindle Touch, which he didn't seem at all confident on. For example, he told them that he "thought" you could upgrade the With Offers model to remove the ads for an extra $30.
There have been some efforts by manufacturers to have product specialists in individual stores. It's never taken off on a large scale; I'm guessing the economics don't work. With cameras, at a store like B&H, you do see employees who are at least nominally more knowledgable about specific brands and won't, in fact, give you opinions between brands. And large photo stores often have days when manufacturers' reps are on hand to answer questions. Of course, this sort of model is far more the exception than the rule. Sales specialists are expensive and it's hard to justify them on low-margin consumer items.
I moved and haven't been down there in about 8 years now, but at the Home Depot I used to deal with, periodically a representative from DeWalt would stop in and do demos and answer questions about their tools.
