JD Lasica enumerates:

1. Saving time
2. Convenience
3. Access to a richer pool of material
4. Zero in on the info you want
5. RSS can serve as an alert service
6. RSS levels the playing field
7. RSS drives conversation

JD adds:

Why is RSS useful to publishers and corporations? Here are ...

5 Reasons Why Companies Should Publish an RSS feed:

1. Multiple gateways. It's another doorway or distribution channel for getting your content in front of readers.

2. Self-syndication. It allows publishers to syndicate content without the involvement of third parties.

3. The predictability principle. By far the most important reason is this: Just as with newspaper subscriptions, RSS subscriptions mean your content is guaranteed to be seen on a regular basis rather than via sporadic pull behavior. On a typical news site, a reader stops by an average of three times per month.

4. Loyalty. RSS can forge a closer relationship with readers if done in conjunction with a weblog or community feedback tools.

5. Future revenue streams. RSS could be a great way of distributing classified advertising and other targeted marketing opportunities as long as the user requests it and finds it useful.