It is these synthetic feeds that become useful to populate more top level web pages. For example, your home page might lead to the fruit page which would lead to the apple, pear and mango pages. So the content of your second level page could be the synthesized feed. And users could subscribe to the RSS feed or the enewsletter. However comments would be in the apple, orange or mango archives (permalink) page.

Another option for synthetic feeds is to create personalized pages. Instead of creating separate areas on a page like MyYahoo or Netscape.com, let the user select their feeds and then combine them into one. So in one area they see all of the latest news.

So synthentic feeds provide you another level of content.