Netflix has released a step-by-step guide to making socks that are designed to do more than just keep the feet of binge-watchers warm and cosy. The Netflix socks detect when the wearer has fallen asleep and pauses the currently playing program to prevent them from losing track of their favorite show.
The Netflix socks require some practical knowledge of electronics, programming, and soldering, so it's fair to say these aren't aimed at the mainstream public, but rather at the maker/geek community. If you're making the socks from scratch, you'll also need some knitting skills, but you can use an existing pair of socks if need be.
The socks work using a combination of an Arduino microcontroller, an accelerometer, a momentary button, a battery, and various LEDs. Once put together using Netflix's guide, the socks use actigraphy to detect when the wearer has fallen asleep. This essentially involves tracking the wearer's movements, with the socks sending a signal to pause playback when the wearer has remained inactive for a set period of time.
For more advanced sock-makers, the guide suggests adding a pulse sensor to the socks to improve accuracy or embedding a 2.4 Ghz transceiver to send wireless signals to an infrared repeater if your socks aren't in line of sight of the TV.
It's worth noting that these Netflix socks are only useful because Netflix skips to the next episode of a show automatically by default. Sure, doing so keeps people watching for longer by encouraging binge-watching, but it can also lead to the problem Netflix is itself now remedying.
The bigger issue with Netflix socks is that they're far too complicated for the vast majority of people to even attempt making. They're also expensive (at US$60+), and not really what you'd classify as a necessity, which means this is little more than a marketing exercise that pushes the idea of binge-watching as we head into the holidays. But as far as marketing exercises go, it's not a bad one.