I do not want to be negative here, just realistic. If you want reviews you must be persistent and steadfast. I will use my book for example.
My book http://www.amazon.com/dp/B006XG0ID4/ref=r_soa_w_d
has over 40 reviews and has consistently been in the top 5 books on Amazon for the two categories it is under. I have had many emails about the book too. It has been downloaded thousands of times and most of the reviews are from Amazon readers that I do not know. I say this to point out that some people obviously like the book. That said I cannot tell you the number of people who have told me they will review the book and have not. It has been well over 100.
I can honestly say this because I have had close to 300 bulk orders for the book in print to be used in outreach's (they must have liked the book to order books to hand out, some orders were for several hundred books) and only 43 reviews. We gave out 4,000 copies at a Christian concert in Michigan last summer to mainly believers (to read and hand out) and we specifically asked them for a review. To date I do not think any of those people reviewed the book. I know an author who has had 6,000 copies of an excellent book downloaded during a free period on Amazon and only a handful of reviews to show.
You need reviews but getting enough reviews is not always easy. If you want them you need to be bold and ask and follow up. Unfortunately Christians are not always the most reliable as it seems they should be. You need to network and FaithWriters is a great place to do this. I know that Dave's book is being read by another member we referred it to and it will produce another review.
If your book is in the Free Reads for Reviews program http://ebooks.faithwriters.com/readsfor ... tbooks.php
you need to be diligent and get the interested party a copy as soon as you can after their request. Prepare and be ready for requests so you do not need to scramble when you get one. When you send them the book let them know just how much you appreciate their offer and how you are looking forward to their review. Follow-up on those who get a copy. Do not look at it as if they owe you something because you gave them a copy of your book for free. Be appreciative and thankful towards the reader. Be an example of Christ.
We are also running an incentive for FaithWriters members to read and review books. The top reader and reviewer will win $150.00 The link can be found on this page http://ebooks.faithwriters.com/readsfor ... tbooks.php