You can link other products to a listing, which will be shown to potential buyers when they are looking at a certain product. 

Upsells - These are products which you can ‘recommend’ instead of the product a potential buyer is viewing. For example, if you have an alternative listing that is more profitable for you, better quality or more expensive to purchase. 

Cross-sells - These are products that will appear when a customer has added the product to their basket. You can promote other sessions that might be of interest to the customer, based on the product they are purchasing. 

You can add upsell or cross-sells in the “Linked Products” section in the Product Listing page. Start typing the title of the product you want to add and select it from the dropdown box.