A sitemap is navigational tool that lists every accessible page in the site according to the site hierarchy. There are two basic kinds of sitemaps: One that is designed to be read by humans, and the other designed for visiting robots, crawlers and spiders.
Your site should have both kinds of sitemaps, and they should be updated whenever new content or products are added to your store. If your Ecommerce platform doesn't automatically generate sitemaps for you, you can take matters into your own hands and make them yourself.
HTML Sitemaps (for Humans)
The HTML sitemap it like a table of contents and is usually linked to from the footer of the site. It can be formatted any number of ways, as shown in the following examples from leading Ecommerce sites:
XML Sitemaps (for Spiders)
XML sitemaps are designed to extend a helping hand to visiting robots, crawlers and spiders. The sitemap tells search engines how often your pages are updated, the last time each was modified, and the relative priority of each page. The sitemap file (sitemap.xml) is placed at the root (or topmost) directory of your site where it can be easily found whenever your site is crawled. XML sitemaps are one of the most effective ways to ensure that your site is listed in the major search engines.
Its companion file robots.txt, contains additional instructions for the visiting robot. For example, if you don't want every part of your site indexed, you can say, "Don't bother to look in this folder, and stay out of that folder over there." This is not to be mistaken for a security measure in any way, and will keep out only those robots that follow the rules.
After your XML sitemap is in place, you should notify Google through your Webmaster Tools account. (If you don't have an account, you should set one up now.) Here's a checklist of everything you need to do. I always seem to have trouble finding my way around Google's site because they keep moving things around. If you have trouble finding their Webmaster Tools, you can always go to their sitemap and look under Webmaster. While you're at it, you might want to check in with the other major search engines, including Yahoo, Ask and Bing.
Sitemap Generators
Although sitemaps can be created manually, it's a whole lot easier to use a program that automates the process. There's a wide range of software available, much of it for free. Here's a comprehensive list of sitemap software, including Google's own Sitemaps Generator.
My Mac-using friend Bob has had good results with Google Sitemap Automator from Rage Software. It's easy to use and is available for both the Mac and PC. A free trial version can be downloaded from their site, and the standard version can be purchased for $29.95.
XML-Sitemaps.com is an online service that will generate a sitemap up to 500 pages at no charge. I have used it several times and it takes about eight minutes to generate a 293-page sitemap. When the code is complete, you can copy and paste it to Notepad, save the file as sitemap.xml, and FTP it up to your server. Then make sure to let Google know that you have an updated sitemap and that your site is ready to be crawled. The unlimited version of Sitemap Generator can be purchased for $29.95. It supports larger sites and can be run as a chron job, which means you can set it up to run on schedule.
Visual Sitemaps
PowerMapper is the Cadillac of them all, and generates a wide range of visual sitemaps -- in addition to the standard text-based HTML and XML. As it scans the site, it captures meta data and generates a thumbnail of each page, and then uses the information to create a map. Each map is fully hyperlinked, so you can drill down and jump to a specific page.
A visual sitemap is a great planning tool for anyone who designs or manages a website. It sure beats crawling around on the floor with Post-It Notes! (That's not what is usually meant by "crawlers," but just ask any information architect who has been around for awhile...)
PowerMapper makes it easy to apply different mapping styles once the data is in place. For example, if you want to illustrate the site hierarchy, you can choose from a number of thumbnail map styles. However, to emphasize the site structure and content clusters, you might prefer the Skyscraper style where the height of each block indicates its relative distance from the home page. Sitemaps can also be exported as graphic images (PNG) for use in presentations and reports.
PowerMapper Standard includes seven map styles and exports XML sitemaps. The price is $149.00 for a single-user license. PowerMapper Pro includes thirteen map styles, and lets you overlay analytics/SEO data and notation. The price is $349.00 for a single-user license.
Special Note for Magento Users: PowerMapper needs some additional instructions to find its way around a Magento site. If left to its own devices, it will map every link it finds, which can easily turn into 16,000 or more. (You don't even want to go there!) I contacted the company and they discovered that the Compare Products links cause it to produce more and more pages with new combinations of products. There may be similar issues on sites which allow you to apply filters to lists of products, such as Clothes - Trousers - Blue. (They're in the UK.) So be sure to add the following lines to the blocked links box before you map your site. Here's how:
On the View menu, click Options. On the Blocks tab, type the following code into the Block Links box. Then, click OK to save the instructions.
*/customer/account/login*
*/checkout/cart*
*/catalog/product_compare*
*?*
I tested this code with a Magento site and it reduced what had previously been over 16,000 links down to 800 or so. It took about an hour to map the site. And of course, you can experiment with different instructions to see what works best. You might use the Block instructions to exclude certain areas so you can focus on a certain part of the site.