Redbox is a physical rental, not a digital.

I used to work at Amazon (in a different area, but collaborated with people in the video business) and I now work for a company that competes with Amazon's transactional video service.

The world of physical rental - at least in the US, not commenting globally - can rely on the First Sale Doctrine, which dramatically alters the economics.

https://en.wikipedia.org/wiki/First-sale_doctrine