FeedBurner is a new service that enhances RSS or Atom feeds by providing personalized usage and trend statistics that describe how the feed is being used.
It works by creating a FeedBurner based URL for an existing RSS feed. It provides various stats, such as which links in a feed subscribers are clicking through, auto-inserts your Associate ID into any links to Amazon.com catalog items it finds in a feed and a few more things.
Also in the works are the following interesting services.
Authentication services for premium or private feeds, namespace and feedsplicing capabilities that enable interesting new feeds with rich content, “future proofed” feeds that enable conversion between feed formats, and many many more publisher services.