When your content talks about something related to a product or item that is available on Amazon or eBay, add a capsule beside.
When you are recommending a product or item, add the Amazon or eBay capsule with your mentioned product.
When you want to recommend a range of similar products, add the Amazon or eBay capsule.
When you want to give your reader some place to find the product, add the Amazon or eBay capsule.
Key - Relevant