RSS feeds are great for exposing your users to fresh content and promoting your site to search engines, but they do have some potential drawbacks. For starters, RSS feed recipients may no longer visit your site, although most RSS feed publishers say that the feeds generally lure people in. Another possible pitfall is the amount of time it takes to keep creating fresh content. If you fail to publish new content on a regular basis, your site or blog will not only lose its utility to those who read and subscribe to its RSS feed, it will also lose favor with search engines.
For more on RSS feeds, be sure to read Widen Your Web Site Audience with RSS Feeds.