A person forwards an ad to someone else, that person buys later on a different device, and the platform has no way to connect the two events.
On one documented account, roughly 12% of link clicks on its ads also generated a share, someone forwarding the ad to another person entirely rather than clicking through themselves.
One worked example from that account: a single ad pulled 6,500 clicks and 2,600 shares. The forwarding pattern skewed toward an older, highly active audience on the platform sharing to a younger relative who was actually in the buying age range for the product. That person converts later, on a different device, with no shared identifier connecting the two of them at any point.
The ad platform's own reporting can see that a share happened and can see that a purchase happened somewhere. It cannot resolve those into one story, because nothing in its own data ties the sharer's device to the buyer's device. That conversion lands as direct, organic, or unattributed instead of paid, not because the ad failed, but because the reporting layer was never built to follow a human relationship. An owned record reconciled against the business's own new-customer data is the only place with a real chance of catching a pattern like this one at all.