With its single-serving coffee pods, Green Mountain Coffee has transformed the business of brew. Pop a capsule into one of the company's Keurig machines, and the machine will instantly churn out your daily caffeine dose.

But Green Mountain doesn't want copycats taking the business it pioneered away. That's why CEO Brian Kelley says its new coffee makers will include technology that prevents people from using pods from other companies. The approach has been compared to DRM restrictions that limit the sharing of digital music and video online. But more than just curbing your coffee choices, Green Mountain's protections portend the kind of closed system that could gut the early promise of the Internet of Things – a promise that hinges on a broad network of digital, connected devices remaking the everyday world.

>Green Mountain's protections portend the kind of closed system that could gut the early promise of the Internet of Things

For now, Keurig coffee makers aren't Internet-connected devices. But Green Mountain's decision – which effectively has them adopting a printer-ink business model, where they make money on the refills, not the machines – shows exactly how the makers of Internet-of-Things hardware might not be as interested in openness as idealists might hope.

Take, for example, the "smart fridge," which for years has floated around as a way the Internet of Things will make life in the future easier. Such a refrigerator will read, say, RFID identification tags on the products inside. When one of those IDs goes missing for a long enough time, the fridge will assume that you're out of that product and will order more from the online grocery delivery service.

Less often considered, though, is the business model that would underwrite such a setup. It's easy to imagine a smart fridge subsidized by Amazon or Walmart that will only order new products from those retailers. Just as cell carriers are more about selling you gigabytes than handsets, the money in the smart fridge is in the re-orders, not the digitally enabled icebox itself.

In a paper for Harvard's Berkman Center for Internet and Society, the scholar Paul Kominers argues that one defining feature of the Internet of Things will be interoperability, i.e., its devices will need to be able to send and receive signals from one another and, more importantly, to understand what those signals mean. Kominers gives the example of the SMUG, a "smart mug" that stores your previous drink orders and payment information. As initially designed, he says, the SMUG only works with select coffee shops for select products. To live up to their promise, SMUGs would need to increase their interoperability. "The more SMUGs coffee shops accept," he writes, "the more useful they become."

Hospitals That Can't Talk to Each Other —————————————

Limiting the interoperability of the Internet of Things could also restrict systems far less trivial than coffee or kitchen appliances; it might have the greatest impact on infrastructure, in important questions that get decided far from the eyes of everyday consumers. As Kominers points out, hospitals are starting to benefit from interconnected sensors, which are finding their way into everything from medication dispensers to doctors' pens to even (though monitoring devices) the patients themselves. One might hope that hospitals would ensure interoperability within their own internal systems. But without open standards, one hospital's "Intranet of Things" might not be able to talk to another hospital's network, causing much usable data to be lost.

Photo: Ariel Zambelich/WIRED Photo: Ariel Zambelich/WIRED

Kominers gives another example of smart water management systems. For such a fundamentally interconnected network as the water supply, the systems managing the flow from one district to the next should be able to talk to each other. But if two different companies make smart water systems, they may not want to expose competitive secrets by enabling them to talk to each other. Such collaboration could even run afoul of antitrust regulations.

Ultimately, Kominers argues, the obstacles to a wide-open Internet of Things are more likely to be organizational than technological. "Because many (Internet-of-Things) systems are being developed separately, by different firms under different proprietary standards, it is unclear how interoperability will emerge on the systemic level, or if it ever will," Kominers writes.

In other words, you only get to drink the coffee we say you can.