Hi @DRMax,
I think you’re on the right track here so far. Just to be specific, I see you’re on the Shopify platform, so a Fulfilled Orders happens exactly when an item is marked as Fulfilled in Shopify’s backend. For most merchants, this is when an order has a shipping label or when their fulfillment centers have processed the orders and their systems marks those orders as Fulfilled through Shopify’s API.
Ordered Product event is a specific event that is sent for each item that is purchased. So when a Placed Order event happens and the order has more than one item, then there could be multiple “Ordered Product” events that happens subsequently (and almost immediately) for each item.
Each event has a different set of data, but many data may overlap in each event. For example, Fulfilled Order, Placed Order, and Ordered Product all have at least one Item that was ordered. This article from Klaviyo describes a bit more detail of each of these built-in events:
For your particular scenario of creating a Segment per product ordered, I would go with “Ordered Product” with an AND condition that there is no Cancelled Order (with that Product) AND there is no Refunded Order (with that Product). It’s a bit tedious to setup for each of your Products, but that should give you the proper rules to ensure that they they truly made the purchase.
Hope this helps!