SEO (Search Engine Optimization)

Dynamic sitemaps
An absolute must have to improve page rank (listing in the search results). The module is used to submit dynamic links of your store content to search engines that work with the scheme from sitemaps.org. (Google, Yahoo, Live).
Link: http://www.oscommerce.com/community/contributions,3306

Dynamic Meta Tags
This contribution creates dynamically unique title and meta tags for products and categories, this will prevent that your pages will be seen as doubles by the search engines.
Link: http://www.oscommerce.com/community/contributions,3726

Image enhancements

Auto thumbnailer
The module create on the fly a thumbnail from the original image. This way, thumbnails showing in listings will be much smaller in size, seriously improving the loading of your pages. Also it prevents the need for using multiple images, like a big image in the popup and a small image in the listings.
Link: http://www.oscommerce.com/community/contributions,2226

Lightbox image
Based on the Lightbox Javascript, this modules creates a fancy preview of the product instead of using the standard osCommerce popup.
Link: http://www.oscommerce.com/community/contributions,5532

Product promotion

Featured products
Promote specific products by adding them to the front page, getting them directly under the attention of the customer.
Link: http://addons.oscommerce.com/info/651

Cross sell
Link your products to each other, boost up your sales by suggesting other products to your customers.
Link: http://addons.oscommerce.com/info/1415

Product management

Easy populate
A way to easily populate your store with products and categories. Up- and download the store content from and to your favorite spreadsheet.
Link: http://www.oscommerce.com/community/contributions,500

Quick price update
This contribution allows to quickly update the prices of all your products by simply editing them through one form.
Link: http://www.oscommerce.com/community/contributions,122

Low stock report
Keep track of the current stock level from your product. Instantly manage stock levels, product availability.
Link: http://www.oscommerce.com/community/contributions,1245

Information management

Google analytics
Keep track of customer behavior on  your site by advanced analytics and e-commerce analysis.
Link: http://www.oscommerce.com/community/contributions,3756

Orders tracking
Comprehensive set of tools for gathering information about purchased items, customer behavior and a lot more.
Link: http://addons.oscommerce.com/info/1522

Margin report
Generates the ability to create a report based on value / percentage margins.
Link: http://addons.oscommerce.com/info/1594

Inventory value report
This contribution allows you to see how much you have invested in inventory and its current value.
Link: http://addons.oscommerce.com/info/5387