So what happens if the company that sold you that song goes out of business? Very quickly, things go from being complicated to becoming a “super complex” problem, Hunter told me. Apple’s document outlining terms and conditions for purchases from the iTunes and App stores is nearly 80 pages long. “Good luck working out if you still have a right to use the music if Apple goes out of business,” Hunter said. “I’d have a hard time working it out, and I’ve been a copyright lawyer specializing in high-tech issues for 25 years.”

For streaming purchases, the unfortunate fate of one’s collection is pretty straightforward: “Let’s imagine Amazon goes out of business,” said Siva Vaidhyanathan, a media studies professor at the University of Virginia. “In the case of streaming videos, yeah, you just lose it. It’s just not stored locally.”

In other words, unless you’ve taken the time to download each title you purchase to stream—Amazon recommends you do this “promptly after your purchase” in its Instant Video Terms of Use, by the way—your access to that film depends on a variety of factors, all of which are outside of your control. Amazon, which didn’t respond to multiple interview requests for this story, doesn’t even have to go out of business for you to lose the film you bought.

In order to keep a film in your collection watchable, there’s a constellation of pieces that must be in place: The software that streams the video has to work, the devices you want to use to run that software have to remain compatible with it, and the film itself has to be accessible on that software. None of these things is guaranteed. The films you buy could already, at any time, automatically disappear from your Instant collection. (Again, that's right there in the Amazon service terms.)

All this signals a larger cultural shift in the way people think about ownership of media in the 21st century, or how they ought to be thinking of it. Increasingly, the purchase of digital works is treated like the purchase of software, which has gone from something you buy on a disc to something downloadable with an Internet connection. “You might think you’re buying Microsoft Office, but according to your user agreement you’re merely leasing it,” Vaidhyanathan said. “You can think of music and video as just another form of software. There is a convergence happening.”

That convergence is built for a streaming world, one that’s driven by an expectation of instant gratification. “One of the things we’re doing increasingly is opting for convenience over dependability. And we’re doing it somewhat thoughtlessly,” Vaidhyanathan told me. “We have to recognize that it is temporary. Anything that is centrally collected in a server somewhere on Earth is ephemeral. Even if Amazon doesn’t go out of business in 20 years, Amazon will not exist as we know it in 100 years.”