2. Nest Lab

Nest Labs is the second largest private company acquired by Google till today. Nest Labs is a home automation company, involved in manufacturing and designing of Wi-Fi enabled, sensor driven, self learning and programmable thermostats and smoke detectors.

On January 14, 2014, Google acquired Nest Labs for $3.3 billion. The reason for this acquisition was predicted as Google wanted to strengthen its roots in the web –connected household appliance markets. Now that was a sharp move by Google in firm footing into the growing market of urban households.

3. DoubleClick

DoubleClick is an online advertising company that develops and provides Internet ad technology. In 2007 Google acquired DoubleClick for 3.1 billion. With such an acquisition Google stepped into display advertising.

Today Google’s display ad network has generated over $3 billion in 5 consecutive quarters from the ad revenues. It is interesting to note that DoubleClick is 2 year older company than Google, still Google has put a hold over it, now that’s a catch.