Allowing website visitors to receive your content via RSS is important for several reasons:
- Permits users to get content the way they prefer
- Avoids email filters that may incorrectly filter your message based on content
- Another way for search engines to spider your website to have more content in the engines
Often websites use an icon like 
to indicate that RSS content is available.
Broadcasts are published to a web page for many of the same reasons you would use an RSS feed.
The difference with the Newsletter Hub is that someone visiting your website can click directly to the hub and view your newsletter content without the need for special RSS readers. This allows you to instantly have new email newsletters published to your website without having to do this manually.