Google's purchase of Nest indicates that Google wants to control the "internet of things" — and entice people into handing over lots more information about their lives to Google.

If you want something to figure out that it should turn up your home thermostat because you're heading for home and the day is cold, there is no a priori reason why that should involve any company's server. That computation is yours, personally, and need not involved anyone else.

Google wants it to involve a Google server, but doing it that way is SaaSS (service as a software substitute).