Why is a Site Map important for a web site?

An important point to remember ALWAYS is that people come to your site looking for information.
Net surfers are a ruthless lot. If they find information quickly, they stick around; else, they click the "Back" button on the browser, close the browser window or simply go to another web page.

So the most important reason a site map is indispensable is because it helps the visitors to understand the site structure and layout and thus, quickly gain access to what your site has to offer.
A site map is a page wherein the structure of a web site is clearly shown to a visitor. They can then choose the page to which they want to go with just one click.

In addition to the advantages a site map offers to "human" visitors, it is also important for "robotic" visitors from search engines. As a web developer your aim should be to get all public pages on your web site in the search engine database. Since a site map carries links to all pages from one page, it is an ideal candidate to submit to a search engines. Submission of the site map to a search engine might help in getting all web pages indexed quickly by the search engine. I may be incorrect since I have no data to support this point but it just seems logical. However, on a similar note, there are search engines that limit the depth of searching on a web site from the homepage. For example, if you have a page buried deep inside the directory structure on your web site, it might not be picked up by such search engines. In such cases, the importance of a site map is that it pushes the search engine to go directly to the page instead of hunting for links.

There have been clients of mine who got back saying that their site map ranks higher for a particular key word that the actual page which has been optimized for that key word. Some of them like this while others mention that they would prefer of visitors go directly to the actual page.
So if you don't like the site map on your web site to rank high, you can always use the NOINDEX attribute of the META tag.

Two important links:
1. How does your web site appear in text browsers (and thus to robots) - go to the Lynx viewer -> http://www.delorie.com/web/lynxview.html. This is such a good tool. It lets you see your site how a search engine would.
2. To know how may pages Google has indexed on your web site type "site:mywebsite.com" in the Google search field.

Large web sites might have hundreds of pages. For such sites, the developer might create dynamic and interactive navigations JavaScript drop down menus making it easy for the human visitors to go quickly to a desired web page. However, a robotic visitor would not understand such menus at all and thus, it is very important of such web sites to have site maps.

If you use a JavaScript navigational drop down menu on your site make sure you include a link to the sitemap page inside the <NOSCRIPT> tag. So if a visitor is using a browser which does not support JavaScript or has JavaScript turned off, he or she will at least know the site structure.

A site map helps you in planning your site before you even start creating it. Once you decide which pages you want, your job is actually made a lot simpler when you start designing the web pages. At the beginning of each web site project, I ask my clients for the site structure. This is simply the site map. A site structure helps me in understanding the number of pages on the site and how they would be laid out. For example, if there are only 6 main pages, I would put links to these pages in a horizontal navigation menu. However, if there are more than 12 main pages, I would prefer to go for the standard left hand side navigation menu system as it would be difficult to put 12 links horizontally in one row.
Thus, another important point is that a site map should actually be the first step in planning for a web site.

A final point to push my argument of the importance of a site map - Google in its Webmaster Guidelines recommends that sites should have a site map.

1 | 2 | 3 | 4 | 5 | 6