Whenever I choose a book to read, I almost always read multiple reviewers' comments before I purchase the book. To me, there's nothing more frustrating than buying a used book on Amazon.com or BarnesandNoble.com and not being able to flip through the pages and see if I like the writing enough to read the book.
I can be critical of the books I read, as most readers are. We're all looking for specific things from our reading experience. The clarity and cohesiveness of an author's writing is a major part of the reading experience for me.
Do you like to read book reviews before you read a book?
I know some people that don't. At first, I couldn't understand why they wouldn't want to read what someone else thought and evaluate whether they wanted to invest their time and money on a book.
But after reading hundreds of reviews, and sometimes pausing mid-way through a book in order to read some, I can see how a review can unduly influence your reading experience. There have been occasions that I did not notice a character's flaws, or the over-dependence on clichés, etc., until a more discerning reader pointed them out in their review.
So when I'm looking for a book to read, I find thoughtful book reviews to be incredibly useful to save me both money and time. By "thoughtful" I mean reviews which pinpoint why they did or did not like a book, regardless of the star rating, not reviews that either praise or criticize with abandon.
When I read a review, I'm looking for several things. Those, more or less, correspond to what I notice when I read a book. This can be the quality of character development, or the uniqueness of plot, but also writing style, and anything that a reviewer points out about which strikes a chord with me. For example, if a writer uses too many similes to the point where a reviewer has complained about them, I can be certain that I'll probably notice, too. (However, there is the chance that when I read a review like this, then buy the book anyways, I will notice it now--whether or not I would have without reading the review.)
Do the pros of reading a review outweigh the cons?
For me, yes, the pros of reading a review far outweigh the cons.
I want to know that the book I'm going to pay money for has many critical readers and that it can stand up under the weight.
The Best Sellers list is one instance where reading reviews really comes in handy for me. I poll a selection of each "star" rating. I'll look at a few 5 stars, a few 4 stars, 3 stars, all the way down to 1 starred reviews. Until recently, I've rarely read books on the Best Seller's lists. I find that when I do, I'm often disappointed in the quality, and I often agree with the dissenting reviewers.
Reading a dozen reviews from discerning reviewers has saved me a lot of money. If it sounds interesting despite a few bad reviews, and I find myself still wanting to read it but the reviews have given me reservations, I'll check it out from the library instead of pressing "buy now."