Add a step to require new reviewers setting their preferences (and allow current reviewers to edit their preferences) to choose their favorite hashtags (i.e. genres) from a list of featured/popular hashtags (i.e. genres), and the on the Select tab of the Review Team Page only show new review opportunities to reviewers with matching hashtags selections at first. This way reviewers who have matching interests will get first dibs at a book that is available for review. However, if the book is not selected within a certain timeframe (e.g. a week) or if the book has a special deadline then have it shown to all reviewers.