This is a good article explaining why book reviews are helpful to an author:
Have you read a book?? Consider leaving reviews!! I don't always remember to go to post on Amazon but after a nudge I will! Authors feel free to nudge accordingly! #Repost @karenakinsya with @repostapp. ・・・ THIS! Your reviews really can make a huge difference in an author's sales. Especially new authors like yours truly. 😉 . . . . . . Repost @trishaleaver ・・・ Reviews really do help authors. Consider giving your favorite author a little shout-out in the form of a review. Because every author could use a little boost!!!