Recently I was in a content workshop we held to share with other member of our department that are responsible for marketing and communications.  We were briefly explaining what RSS was and I said essentially that the most important thing about RSS is that a user does not need to visit your website to read your content, listen to your audio or view your video.  For people who don't use it and are accustomed to controlling the design and layout of content, this is extremely important to understand.

I gave the example of news organizations who will subscribe to RSS feeds from all the new release pages (if there is a feed) and this would allow the press to keep up with the organization's announcements without visiting several websites every day, which they are unlikely to do.  RSS pulls any updated content to them so that all they need to do is open their RSS reader.

This idea leads to the second most important thing about RSS:  The user is in control of the content they receive and are able to pull from sources, instead of the typical push marketing that is done with TV, radio, print and billboards.