I definitely agree that brand loyalty exists, I just think it's much less powerful than many believe.
I think its importance is overestimated simply because its much easier to quantify than, say, the fun-ness of individual games or the value of innovations like the Wii Remote. Those things are tough to quantify, and therefore get less emphasis than they probably should; brand loyalty, multi-media functionality and other perks get more emphasis than they deserve because they're either easy to pinpoint or have a literal, tangible value.
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