I think that "in general" you're right, but you're forgetting the human aspect. If my uncle is buying something for his computer, it might not care what all of his facebook friends think about computers, but he might VERY WELL care what *I* think, and so he might be curious to see what I like.
In a similar regard, I wouldnt ask my mother where to vacation, but I have several friends on facebook that do a lot of traveling, and I think seeing their experiences might be useful.