Manufacturer mappings – Allows you to add a manufacturer name to your item and provide grouping by manufacturer.
Related products – Allows you to specify other products that will be displayed at the bottom of the product display page.
Cross-sells - Allows you to specify other products that will be displayed at the bottom of the checkout screen.
Specification attributes – Allows you to specify the exact specs of your product for easy display to customers. Often used with more complex items such as computers or electronics where comparisons of exact specs are critical to purchasing decisions.
ACL – Allows you to restrict access to particular types of users. Your product would display only to those that are selected. (Note: this restriction is also available on a per category basis)
SEO – Allows you to specify additional keywords or description that will be added to the meta data which promote higher search engine results. Meta title would override the existing page title, which defaults to the name of the product.