bill - 4:39 am on Nov 11, 2010 (gmt 0)
I'm not sure that RSS is a big help
Compared to FaceBook and Twitter? They're different things altogether...but I have seen FB and Twitter accounts used much like an RSS feed. All they do is announce site updates. You can do that with an RSS feed as well.
Whether RSS is beneficial for your site's visitors is of course up to you. In general it's a means of syndicating your content and notifying your feed subscribers of changes to your site.