First, OP, thanks for the reminder. I just went and reviewed my last five purchases at Amazon!
Second, there was a poll I read somewhere (I'm looking, I'm looking) that rated the top five things that people did prior to buying a book at Nook or Amazon. IIRC the first was put in a generic description, then came a view of all the covers shown on the pages. The third was the title and price.
On Amazon, the title and price are right above the total stars. People didn't mention how many reviews, only the price, and stars. Name recognition was in there somewhere, not sure where. So they went through those steps before ever clicking on a book.
Then, they did one of three things (or two, or three) - they read the blurb and "Look Inside" and a review or two.
What's my point? Like everyone else has said, you must get them to click on your book cover and get them to the actual sales page FIRST. So, IMHO - spend money on your blurb and cover, not reviews. You'll get something like one revieiw for every 100 sales. Not much you can do about that except sell more copies by getting people to search for your book (paid advertising, emails to subscribers, newsletters) and click on a link or that awesome cover.
