The streaming video industry isn't quite the same as streaming music. But as more content becomes available on streaming platforms, the less content people will take from digital downloads.

Here's the rub. Digital download and rental sales have already fallen off the cliff. Self-reported rental and download spend in the U.S. has been cut in half since 2012, according to Parks Associates. The average consumer claims to spend only a couple of bucks a month on downloads.

So while companies with digital video stores like Apple or Amazon.com could see a further decline in downloads, there's not much farther to fall.

From the article "Where Will Streaming Subscription Budgets Come From?" by Adam Levy.