Hi sabahatu1546489 and Frank Breen!It's helpful to think about this in terms of 'recommendation delivery' and 'entity ingestion':Delivery:Many types of recommendation criteria require a "key" off which to base the items to be recommended. For example in a "people who viewed this viewed these" criterion, 'this' is the key. Your page needs to tell us, in the mbox request, the key. In this example, the key is the item being viewed, specifically it is the unique identifier for that item, the entity....