I review my own restaurant online to improve the positive vibe.  Why not, if they let you?  Instead of a bunch of bad reviews the searcher will see my reviews mixed in.  This is a lot easier that actually improving my restaurant.  No I could just pay Yelp to filter out the bad ones but what is the fun in that.  The truth is that the interviews that get posted are usually from those unhappy customers.  The happy ones are not as motivated to post.  I just help the average positive post count.  Jody Rookstool is a good reviewer and will always say something good about your business.