Using sitemaps for SEO

The aim of the Sitemaps protocol is to allow a webmaster to inform search engines about URLs on a website that are available for crawling.

A Sitemap is an XML file that lists the URLs for a site. It allows webmasters to include additional information about each URL such as: when it was last updated, how often it changes, and how important it is in relation to other URLs in the site.

This allows search engines to crawl the site more intelligently. Sitemaps are a URL inclusion protocol and complement robots.txt.

Sitemaps become very useful on websites where areas of the website are not available through the browsable interface, or where webmasters use rich Ajax or Flash content that is not normally processed by search engines.

Webmasters can produce a Sitemap that contains all accessible URLs on the site and submit it to search engines. Since Google, MSN, Yahoo, and Ask use the same protocol now, the use of a Sitemap would let the biggest search engines have the updated pages information.

There is a limit to the Sitemap files however of 50,000 URLs and 10 megabytes per sitemap. Multiple sitemap files are supported, with a Sitemap index file which serves as an entry point for a total of 1000 sitemaps. This will become useful for websites that have thousands of pages on one sitemap.

SEO Programmer
Kenneth Berkley