What use are feeds for a community?

Feeds, such as RSS feeds, are used in two ways. They enable communities to:

Distribute content beyond the people who visit their website. Members and non-members can subscribe to feeds through an aggregator so they are automatically updated through a web portal, news reader or email whenever new content is published to a site.
 
Combine content through bundling feeds into “widgets”, “gadgets” or mobile devises that make it possible to display blogs, videos, slideshows, news headlines etc. into another website. This means that communities can combine and integrate the content from different tools in different ways onto their website.

As the number of communities increases, feeds enable people to manage their participation across multiple communities – a challenge that is becoming central to the usefulness of communites.