Does the directory contain reviewers who request payment in exchange for a review?
Yes, but they are in the minority. Over 90% of the reviewers in our directory don't request payment. The way we see it, our job with this free directory is to connect you with reviewers best suited for you. We want to help as many authors as possible as efficiently as possible, including those who are fine paying for a review. You can filter the search results based on whether the reviewer requests payment.
Warning: Paying for a review goes against Amazon's Terms & Conditions, so tread carefully.