Do book or movie critics affect your buying choices?

Let me start of by saying that this is not about bashing critics. As a writer I want my book reviewed, preferably a positive review.

But I've always wondered especially when it comes to the horror, science fiction, erotica, or other niche genres do people pay attention to reviews. As fans of certain genres you actually get to a point where you don't expect these movies / book to get a positive review. That leads me to my question. Do critics affect your movie / book choices.