Writing reviews is probably one of the very best ways you can help your favourite authors (besides buying their books). On sites like Amazon, once a book has a certain number of reviews the platform "rewards" it by showing it in the "Also bought" lists. Some readers and book newsletters won't even consider reading a book until it has 25, 50, or even 100 reviews. But what makes a good review? Here are the "3 Rs" of writing a good book review.