Related & Upselling Items
Next to the "Options" tab, you will find the "Related Items" tab.
Here, you will have the ability to specify products that you would like to cross merchandise on your store by displaying these additional products on the an individual product's listing page.
Click Add to select which product's you'd like to specify, search and select the product's you'd like to use for this purpose and Save your changes.
- Related Items
Typically, related items will be something that is similar in scope to the product you're editing. For example, a T-Shirt may have other shirts or articles of clothing set as its related items. On the product's listing page, they will be displayed as "Related Items"
- Up-selling Items
These products are typically items that can be baught in addition to the item being displayed. For example, a listing for an MP3 player may have headphones or chargers or memory cards listed as its Up-selling items. On the product's listing page, these items will be displayed as "Accessories"
Tip: You can easily change the listing page's labeling of the related items ("Related Items" & "Accessories") from the Store Language section available in Settings =>Design =>Store Language.