Google will only spend a certain amount of time on your site when it visits. They recognized this as a problem, for both them and the shop owner. So to speed up the process of getting a sites pages indexed, they came up with their sitemap. This contribution will generate a sitemap of your whole site and notify google that it exists. The optional cron option will send google notice on a periodical basis. This is useful if you add new items to your site. If you use scripts found on the web to create your site maps, please be aware of two problems:
Those scripts are not aware of how osCommerce uses session ID's and may include them in the url's. This can be a security problem as well as creating invalid url's. Those scripts are not automatically updated. For the site maps to be correct, they need to be updated occassionally. How often depends upon how often your products are changed. By using the cron option with this addon, this is not an issue. Just set it up (which we do) and forget about it.