This contribution allows you to cross sell matching or coordinating products to customers for almost any use such as completing an outfit, other books in a series, color matching items, etc.... This is done by simply adding product SKUs (product ids) to the product page in admin in the following fashion SKU, SKU, SKU, etc. Then on the catalog product page, three of these SKUs are randomly selected to display as "matching" cross-sell items if they are in stock, allowing you to increase your cross sells and not have to micromanage them. Can be easily added to even the most modified of stores.