I guess I just assumed reviews were only done by "reviewers". Yes, we need reviews from book reviewers and book bloggers. But, we really need input from regular readers, too. It you liked or loved a book, please take the time to leave a review.
For example, perhaps you loved the fact that the author went into a lot of detail about the homes or settings. That is good to know. Some people love that. Others prefer more dialog driven books. Either way, it helps both readers know what this book is like. If the dialog flows well and is crisp, say so. If you laughed, cried, felt emotions toward characters or situations, say so (again, do NOT spoil a situation by revealing something that should not be).
Conversely, if you did not like a book and feel compelled to leave a review, be specific. Leaving a one or two star review and saying "This book sucked" or "The worst book ever" does nothing but show your meanness. What didn't you like about it? Where the characters wooden? Was plot lacking? Be specific in a constructive way, so that the author can improve their skills. Being mean does not help anyone know what they did wrong. Remember, authors are people, too. Treat them as such. They put a lot of time and their heart into their work. It is ok to criticize the work, but don't bully.
Hey, I know we are all busy. Perhaps you don't have time to do a review every time you read a book. I understand. I don't always, either, even though I know the importance of reviews now. But, if you can take a few minutes, a review is always much appreciated by any author. Good, bad, or indifferent. If you give specific reasons, a review will help other readers and it will help the author.