It started with a Twitter user, @BetoOnSecurity, who noticed the issue on his Android device. Netflix (NASDAQ:NFLX) was asking for permission to track physical activity, likely taking advantage of an update to Android Q.

Not every Android user will see this. Netflix is asking some but not all users of the Netflix Android app to give it permission to track their physical activity. Why would the company need that?

Nothing to see here

Netflix's statement to TheNextWeb, which first broke this story, downplays the test. "This was part of a test to see how we can improve video playback quality when a member is on the go," Netflix explained. "Only some accounts are in the test, and we don't currently have plans to roll it out."

On the go? Does this mean that Netflix is looking for users who are walking or jogging while watching Netflix? Not necessarily (and please don't watch Netflix while walking, by the way). Android Q's "physical activity" tracker can tell if a user is in motion, so it's also a useful way to tell if a user is in a vehicle. So Netflix could be looking for ways to improve video playback quality for people who watch Netflix on commuter trains and subways or in the backseat of a carpool.

Going mobile

Of course, there are other possibilities. One of the most intriguing is the possibility that Netflix might be weighing a mobile-only option for U.S. subscribers. Netflix has a cheap mobile-only subscription option in India but not here in the company's home country. The company has suggested that mobile-only subscription options could become available elsewhere but has not said where, nor has it ruled out the United States.

Netflix can already see which and how many users have downloaded its mobile apps, of course, and the company can presumably also tell what proportion of streaming is done on mobile devices as opposed to smart TVs, streaming boxes, and computers. But Netflix probably does not have a very reliable sense of what proportion of mobile streams are watched on the go as opposed to a user's couch or bed. Getting that kind of information could help Netflix understand how a mobile subscription might be used (and how it might compete with the full Netflix subscription). A cheaper mobile-only option might help Netflix solve its pricing problem as cheaper streaming video alternatives from Disney and other competitors enter the market.

Sweatin' with Netflix

Netflix's answer may not be complete, but all other possibilities are speculative. Perhaps the most speculative of all is the theory playfully put forward by Gizmodo's Victoria Song: Hey, remember Netflix's fitness tracker?

Netflix's Make It series of DIY projects included a fitness tracker that, somewhat amusingly, could perform "personal trainer" tasks like shutting down your video stream if you weren't exercising enough. That's certainly unlikely to be a core feature of Netflix anytime soon, but it wouldn't be out of the question for Netflix to offer a gimmicky promotional feature that allowed users to "earn" their binge-watching with exercise or set personal limits on streaming time that were linked to exercise goals.

Making moves

The boring answer given by Netflix may be the most plausible, but even that explanation doesn't sound quite right. Census data from 2016 tells us that more than 76% of Americans drive to work alone. How many people can possibly be watching Netflix on the go? Perhaps the answer is that this is exactly what Netflix is trying to find out, but it's certainly possible that the real reason for this tracking experiment is a little more exciting than Netflix's statement.