Sometimes yes, sometimes no.
I don't really ever go by reviews on Amazon. I'll read them for curiousity's sake, but I don't puch much stock in them. I do follow a few reviewers on GoodReads, and I often pick up books those reviewers are reading. I already know that our tastes in books are similar, so I usually do well picking up books that they like.
I also like to read newspaper book reviews. I enjoy reading the ones on CSMonitor, and have picked up a few books that have had very positive reviews there, but it seems hit-or-miss whether I end up liking those. On the other hand, when I hear an author interview on NPR and enjoy listening to them, I usually like their book. I do wonder how many authors I am less-than-impressed by over the radio whose books I would have liked had I picked them up.