The Importance of a Sitemap
A sitemap is very important file in the process of building a website, and that is indeed the fact if you made a sitemap for the sake of having one. By highlighting the importance of having a well constructed sitemap, you will be able to tailor your own sitemap to suit your own needs.
1)For Navigation Purposes
A sitemap literally behaves as a map of your site. If your visitors browse your site and gets jumbled between the thousands of pages on your site, they can always refer to your sitemap to see where they are, and navigate through your pages with the utmost ease.
2) For Conveying your site's theme
When your visitors browse up your sitemap, they will get the gist of your site within a very short amount of time. There is no need to get the "big picture" of your site by reading through each page, and by doing that you will be saving your visitors' time.
3) For Site optimization purposes
When you build a sitemap, you are actually creating a single page which contains links to every single page on your site. Imagine what happens when search engine robots hit this page -- they will follow the links on the sitemap and naturally every single page of your site gets indexed by search engines! It is also for this purpose that a link to the sitemap has to be placed prominently on the front page of your website.
4) For Organization and relevance