What is the purpose of Feed Burner FeedSmith plugin ?
The main purpose of this wordpress plugin is to redirect all the readers of your blog/site who clicked to subscribe the default feed of your blog so that those users can also be subscribed and those user count could be added to your feed burner subscriptions no.
How Does it Work
Feed Redirection plugin works by some PHP stuff and user-agent detection, to redirect all feed requests to the FeedBurner feed. It can even redirect your existing subscribers.
Probably the most popular feed-related plugin for WordPress users, FeedSmith is just the old Feed Redirection Plugin by Steve Smith, rebranded as FeedSmith.
You can set it up for both post feed and comment feed.From now on, FeedSmith will be maintained and updated by FeedBurner.
Download: Feed Burner FeedSmith Redirection Plugin