I think it might be related to them charging say $100 instead of $5 for the device and providing "lifetime" (read: "indefinite") access to their IoT Cloud. Except there are no guarantees on the duration of that access.

As a side note, I don't get why they can't find the NPV of actually lifetime cloud compute. Compute costs are decreasing rapidly, so a $5/yr perpetuity has a NPV of $185 assuming 2.7% inflation?