When a reply is made to a comment, a twitter notification (@twittername) will be sent to the original comment author to notify him/her of the reply. The notification will be sent from your Twitteraccount. 
This will allow the users to follow up on the comment and expand the conversation if desired.

CommentTweets

When a reply is made to a comment, a twitter notification (@twittername) will be sent to the original comment author to notify him/her of the reply.

DEPRECATION NOTICE: Twitoaster and its API will be shut down this Sunday (March 20th). That means this WordPress Plugin will cease to function (like any other service relying on Twitoaster API). <a href="http://blog.twitoaster.com/twitoaster-shutting-down" title="Twitoaster shutting down" rel="nofollow ugc">Read the full Announcement here</a>
Twitter Comments system. Give to you readers the possibility to send comments via Twitter! Automatically retrieve Twitter Replies and/or Twitter Retweets to your Blog’s Posts. These Twitter mentions are handled like Posts Comments, using WP built-in comment system.
Here is how Twitter Comments work:
<ol>
<li>You Post an article on your blog</li>
<li>You update your Twitter status (or let the plugin do it for you)</li>
<li>You automatically get all related Twitter Replies and/or Twitter Retweets as comments to your Post</li>
</ol>
The plugin also brings two widgets:
<ol>
<li>Analytics charts showing how many Twitter Replies and Twitter Retweets you are receiving</li>
<li>Listings of your 20 most recent Twitter Conversations</li>
</ol>

Twitter Comments – Twitoaster

Twitter Comments system. Automatically retrieve Twitter Replies and/or Twitter Retweets to your Blog's Posts using WP built-in comment system.

CommentTweets vs Twitter Comments – Twitoaster