Robots file include sitemap

[JohnHuynh]

Hello,

I see that google, facebook and moz... have robots.txt include sitemap at the footer.
Eg: http://www.google.com.vn/robots.txt

_Sitemap: http://www.google.com/sitemaps_webmasters.xml_
_Sitemap: http://www.google.com/ventures/sitemap_ventures.xml_ Should I include my sitemap file (sitemap.xml) at the footer of robots.txt and why should do this?

Thanks,

[yeagerd]

Fore sure.  The reason is that not all sitemap files are simply sitemap.xml it may be sitemap.gzip sitemap.zip or in my case, sitmap_index.gzip.  Also, some people may not be able to include their sitemap at root.

Including sitemap exacts in robots.txt gives a clear directive to each of the search engines exactly where to find your sitemap.  Google and Bing/Yahoo will have no issue finding it as you probably submitted it to them but crawlers like ask.com will usually look at your robots.txt and skip your site if no map is placed in it.