Here are the details from the website:
How does it work?
1. To be considered for membership, you will need to be a Boomerang Books Member, live in Australia, and have submitted at least three book reviews via our website (see the Customer Reviews section on book pages).
2. Once you have submitted at least three reviews, apply here to become an esteemed member of the Critics Club.
2. Once accepted, you will be given access to the Critic Club's exclusive online forum.
3. We will post regular offers of new release and pre-release review books on the forum.
4. The first six Critic Club members to respond to the forum post with their mailing address will be our reviewers for that particular book.
5. We will send the book to the first listed member by post. The first listed member will have 7 days to read the book and mail it (at their own expense) to the second listed member. The second listed member has a further 7 days to read the book and mail it to the third listed member. And so on.
6. Having read the book, each member is required to submit a book review of approximately 300 words on the designated book page on the Boomerang Books website.
7. The sixth and final member on the mailing list is responsible for donating the used book to a local charity, such as the Salvation Army or the St Vincent de Paul Society.
8. Failure to forward the book on in a timely fashion or to submit a book review may result in exclusion from this exclusive society!