The debate between absolute and relative links continues in the SEO world. The individual importance of each link is disputed, but it is generally accepted that absolute links offer better overall SEO value than relative links.
Many believe that absolute links are less likely to cause confusion when search engines index your website. It shouldn’t really make a difference, but many conclude that this is reason enough.
Furthermore, content scrapers and RSS services can legitimately (or not) “repurpose” your content. Is your website not always properly backlinked? This situation argues in favor of absolute links. While this is a minor argument, it’s still worth considering.