1. Write a post encouraging readers to look through your archives (if you have your reviews in a particular place on your blog, point them there), and find the books that they have also written reviews. Tell them to leave a link to their review on your review post. For example, I've written a review for Gods Behaving Badly and Jane Doe leaves a link to her review of Gods Behaving Badly in the comments section of my review.
This is a big undertaking but as Dewey put it, it's 'community building'. Have fun!
Case Histories: A Novel by Kate Atkinson
Dead To The World By Charlaine Harris