"Sitemaps enhances the current model of Web crawling by allowing webmasters to list all their Web pages to improve comprehensiveness, notify search engines of changes or new pages to help freshness, and identify unchanged pages to prevent unnecessary crawling and save bandwidth."
The SiteMaps protocol, developed by Google and supported by all three major Search engines “Google, Microsoft, and Yahoo!” enables site owners to tell search engines about the content on their site instead of having to rely solely on crawl algorithms to find it.”
Vanessa Fox, Google in an interview with WebProNews —”Sitemaps.org, born of historic collaboration between Google, Yahoo and Microsoft, intends to simplify the tenuous endeavor of directing search engines to your site’s relevant content. Thus, sitemaps are garnering renewed focus and while the forge is still hot, Vanessa Fox helps clear the smoke. Who better to press a key member of Google Sitemaps for answers than Rand Fishkin, SEO expert from SEOmoz.org.
Does a duplicate content filter induce duplicate content penalties? What about format preference? Is XML king or can a simple text file suffice? What the hell is OAI-PMH? Given some recent dialog on sitemaps versus other SEO methods, Vanessa reiterates the intent of a sitemap: it should be merely one part of the strategy.
“[Google] Sitemaps doesn’t impact your ranking at all… it helps with the very first obstacle of learning about all of your pages.” It’s about crawling, thus it doesn’t preclude code optimization, site organization or other sensible methods in SEO. It may indirectly allow for better ranking but won’t provide it.
Fox also addresses common concerns such as code to text ratio, priority settings and Google Toolbar’s pagerank reports versus Google Webmaster Tool’s.
“[Webmaster Tools] is a little more accurate, a little more up-to-date… the Toolbar pageranking doesn’t get updated quite as often, of course it’s only one factor. I feel like people get really hung-up on the Toolbar pagerank. People probably spend a little more energy on it than they need to.”