A Customer Checks a Nest Labs Inc. Digital Thermostat at a Store

A Customer Checks a Nest Labs Inc. Digital Thermostat at a Store

David Paul Morris/Bloomberg

Including this week’s announced deal to buy Nest Labs Inc. for $3.2 billion in cash, Google has spent more than $17 billion in the past two years to purchase hardware, software and advertising-technology companies, according to data compiled by Bloomberg.