Interesting tidbit in this Forbes article from Parmy Olson:
Crucial to Nest’s pitch to utilities: its thermostat learns a household’s activity over time through multiple sensors that detect things like temperature and movement, and automatically changes the temperature accordingly. Honeywell’s thermostats don’t detect movement, relying more on customer programming. Also, while Honeywell funnels all user data to utilities, Nest takes over the difficult job of parsing it and managing consumption. “We don’t let utilities control the thermostat. We don’t share the data with the utility. We won’t work with them if they don’t agree,” says Nest cofounder Matt Rogers.
If I read this correctly Nest partners with utility companies to better help with load on power companies, and make things more energy efficient. They don’t seem to sell the user data to utilities, but they are certainly profiting directly from your personal data.
That’s a fine line to walk.