- Google bought Nest Labs, a thermostat and smoke detector maker, for $3.2 billion in January 2014. - Opower saw its shares soar in its April 2014 IPO. - Uber set a valuation record of $17 billion after a new funding round in June 2014. - Airbnb was speculated to be worth $10 billion, more than Hyatt Hotels, in March 2014.