Google just made a huge purchase of Nest Labs, the young tech company that makes smart thermostats and smoke detectors. The Mountain View giant bought this company for $3.2 billion, which is a pretty huge number for a company that's essentially just entered its post-startup phase. Here's why:

Google made the announcement on Monday, Jan. 13, that it would be acquiring Nest Labs, Inc. for $3.2 billion "in cash," stirring up questions of why Google finds the maker of the Nest Learning Thermostat and Nest Protect smoke alarm worth so much. The products themselves are great -- clever, simple, connected, and convenient -- and best-sellers. But, as with every purchase from one of the world's biggest, and increasingly most diversified, IT companies, that's not all Google sees in its newest purchase.

Larry Page, CEO of Google, gave just the briefest, surface-level explanation in Google's announcement, basically saying that his company was interested in making more connected home appliances:

"Nest's founders, Tony Fadell and Matt Rogers, have built a tremendous team that we are excited to welcome into the Google family. They're already delivering amazing products you can buy right now--thermostats that save energy and smoke/CO alarms that can help keep your family safe. We are excited to bring great experiences to more homes in more countries and fulfill their dreams!"

Nest founder Tony Fadell divulged a little more of the new Nest/Google vision in his blog post. "From the beginning, our vision was to create a conscious home. A home that is more thoughtful, intuitive -- and nice to look at. No one had cracked the code and we were confident we could do it with the right product, the right team, and focus," said Fadell. "Google will help us fully realize our vision of the conscious home and allow us to change the world faster than we ever could if we continued to go it alone. We've had great momentum, but this is a rocket ship. Google has the business resources, global scale and platform reach to accelerate Nest growth across hardware, software and services for the home globally."

Beyond that, Google isn't just buying Nest and its products. It's adding Tony Fadell -- a notable ex-Apple designer who led the project that created the original iPod -- to its team.

And designing products for the home means more than just a new revenue stream for Google. It's a new source of information. Nest's devices, and the smart home devices in its future, have sensors that can collect all kinds of data -- from the energy use of homes to the patterns of daily life when people aren't actively using an internet connected device.

Google already pretty much knows how everyone uses the internet through computers and Android platforms, so finding a way to get a view into other aspects of life only makes sense. This is no conspiracy theory -- Google's imperative to collect as much data as it can is baked into the company's DNA. It's so apparent with the Nest merger that Nest put up a separate blog post ensuring that Nest data will only be used to improve on Nest's products and services. But Nest's CEO has also clearly made no promise that it would never amend its privacy policy to suit

Google will also get a foothold into the approaching "Internet of Things," where interconnected devices -- beyond computers, tablets, TVs and smartphones -- in the home will provide services, automate life, and most importantly, provide companies data, and therefore, insights about what to sell us.