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Uses of RSS and SEO
External Sitemapping: A new website has new pages and a new page needs to be indexed into Google before it can be ranked into Google's top pages. So what is the best way for Google to find a page? From an external link. RSS syndication can be used to link back to your own unindexed page.
Content Repurposing: Reuse your valuable posts by posting your RSS into other webpages. You can do this through mashing several RSS feeds together. Or just place your feed URL into your favorite Social network like Facebook (the notes section makes this easy)
Rev Up Your Own Content: Sometimes you may want to give your page more relative content. You can mash an RSS feed of your favorite posts and provide it on a webpage. Be sure to provide proper attribution as copyright laws require.