RSS feeds are only as good as the number of subscribers they have, so to gain more exposure for your pre-packaged bits of content, Andy MacDonald suggests registering with as many feed directories (and blog directories, if applicable) as possible.
Make sure you include a link to your feed on your Web site, preferably with the universally known orange RSS button, and write up a short description so that users know exactly what content they're getting with the feed. Enabling auto-discovery of your feed can also go a long way toward increasing subscriptions.
Try including a link to your RSS feed at the end of your email signature, possibly even on your business card or brochure, and if you pen content for other sites, add a link to your feed in your byline. Lastly, get the word out offline.