Using the Comment Luv plugin helps increase comments on your site. When a comment is left a link is added along with the comment to the commentors last blog post. Therefore the commentor is encouraged to leave comments on others sites which use the Comment Luv plugin as they will receive a link to their site. This is a nice reward for their post and encourages comments on your site and additional web traffic. Of course you can still moderate the comment and if their comments are not relevant you do not have to accept them.
Here is an excellent video of the latest version 2.9 of the plugin.
Get the new plugin here : CommentLuv.com
Find the entire Comment Luv community here : ComLuv.com