It's about volume. Sure the movie companies will be giving away their films for free. But if you give away enough films for free it becomes profitable!!
It's obviously implied in this suggestion that they would charge... an element of Popcorn Time's appeal is that it's easy to use and works, unlike virtually every paid movie streaming/download service in existence.
At various times, books, e-books, and kindle fires.
Amazon actually shifted the pricing on books and e-books by selling them at below what they were buying them at for prolonged periods of times, and drove rival book sellers out of business by doing so... and then didn't raise their prices.
Do we know if they still sell books at a loss? I'm guessing with their volume and many competitors killed off they have an insane control over their own buying cost and can force that price to now be profitable, but it'd be interesting to know either way.
Well, from their earnings reports, their gross revenue has grown dramatically but their profit margin remains near zero because they spend every additional dollar they make on growing the company.