If there is one SEO technique that consistently shows up on everyone's site optimization checklists, it's XML Sitemaps. They're certainly not a new SEO technique, but they are often misconfigured or forgotten which leaves the site handicapped.

Introduced by Google in 2005, XML Sitemaps help search engine robots better crawl web sites and be informed of changes to the sites quickly. Before this standard was introduced, many webmasters used HTML based sitemaps for the same purpose, however the XML sitemap protocol is a far more robust method and has eliminated the need for HTML sitemaps (unless your site uses them for human visitors). XML sitemaps aren't for human/browser viewing, they are only used by search engines. Let's dig into the details on this must do SEO practice.

XML Sitemaps are a text based file that function as a very detailed map for search engine spiders to discover content on a Web site. They are simply a text file with a list of URLs that you can make available telling a spider what files are on your site.

Sitemaps also make use of metadata to help spiders discover when a file has changed, when new content has been added, and they are very useful to describe rich media content like videos and images. The XML Sitemaps Protocol that defines the format of all the different types of metadata is available at: www.sitemaps.org.

In the past many Web sites used an HTML format (Web page) sitemap to help a search engine find all the files on...