As more aspects of our lives become connected to the Internet, ads are going to be popping up in more places in our lives, too. And if Google has its way, that means ads on your refrigerator, wristwatch and home thermostat.

In a letter written to the Securities and Exchange Commission at the end of January and made public yesterday, Google said that it is becoming increasingly difficult to define what is considered a “mobile” device for the purpose of calculating advertising revenue. The company sees new platforms for mobile ads evolving in the next few years.

“We expect the definition of 'mobile' to continue to evolve as more and more 'smart' devices gain traction in the market. For example, a few years from now, we and other companies could be serving ads and other content on refrigerators, car dashboards, thermostats, glasses, and watches, to name just a few possibilities,” Google wrote. “Our expectation is that users will be using our services and viewing our ads on an increasingly wide diversity of devices in the future, and thus our advertising systems are becoming increasingly device-agnostic.”

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This prevalence of Internet connectivity in home devices, gadgets and wearables is dubbed the “Internet of Things” – and it's an arena in which Google is eager to play. Earlier this year, the search giant bought the Palo Alto, Calif.-based creator of the Nest smart thermostat for $3.2 billion in cash. Nest embeds Internet connectivity to home thermostats, too.

In its letter, Google also says that while tablets were initially firmly in the “mobile” category, consumer use of tablets more strongly aligns with the way consumers use desktop computers than the way they use mobile devices like smartphones.

“In a short period of time, the meaning of ‘mobile’ at Google has shifted dramatically to ‘handset’ from ‘tablet + handset,’” the letter says. 

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