As an HVAC contractor, this is what I would do with a rooted nest:
1. Display my company logo, phone number at appropriate times.
2. Automatically contact me if my customer has a system failure
3. allow me to push maintenance reminders or specials at appropriate times.
If I had that, I would:
-Make these devices available free for all of my customers with paid annual agreements (but retain ownership)
-Periodically upgrade/replace them as the equip technology advances.
Currently, a lot of HVAC contractors are suspicious of smart thermostats because the feel it is a means for someone else to contact and direct business to their customers. If they were able to benefit from the above changes, they would be buying a whole lot of them.