Do we really pay attention to reviews?

Or maybe a better question for what I'm thinking is when should we put our faith in them.

Mostly, I check out reviews after I've read a book. I'll peek on Amazon and see how many others thought that it was the best story since the last one that totally captured my imagination, or how many also thought "I paid money for this?"

Recently, I've used reviews to sort of rank books. Having grown up with movie critics that rarely like the flicks I adore, but rather praise the sort of films I can barely sit through, I only take the opinions of those who have proven they have similar taste. Yet, since joining Facebook, I've got a To Be Read list a mile high. A bunch of writers friended me, and I'm pathological in wanting to support them. Reviews help me to put books in their place from "OMG, gotta read that right now!" to "How bad can it be? I'll get to it eventually."

Lynn Flewelling's fantasy has earned a permanent place at the top of my list. It's only through a combination of wanting to reread the Night Runner series before picking up the last installment and having so very many books on hand that I stumbled across Homophobic Content in 'Shadows Return' before I formed my own opinion. As it was, I stood in a bookstore, novel in hand, frozen with doubt. In the end, I bought the new (to me, at least) Keri Arthur book and a debut novel that had a blurb by Patricia Briggs (if Patty likes it, who am I to doubt?).

That review really threw me! My first reaction was anger; how could she?! Then denial; surely the reviewer misread! I looked for other reviews and found only the unhelpful from "you/your books are so great! (on the author's blog) to "yay, you get to read about the characters you love again!" (because...that wasn't implied by this being the next book in the series?).

So how much should this one review affect me? Flewelling has given me six fantastic books in two great series...should I deny my reading pleasure based on one person's opinion? Should I ignore the opinion and perhaps set myself up for bitter disappointment?

What would you do? How much attention do you pay to reviews?