What sort of audience are they catering to? Why would someone rent movies on top of a paid subscription?
Also part of the problem the streaming services have is that people don't want to have multiple services, so part of the theory might be that if zizekonstreams offers rental then the people who have memberships might be willing not to switch services to get other movies they want, as long as they can stay on that one service and on demand pay a small fee for the movie they don't have for free.
In my opinion there are a number of ways to handle these issues to provide user value, and that offering rental is one of the least interesting. Unfortunately I have not managed to get a project for trying out / testing some of the potential scenarios.
I was hoping to get a project at NuuDay in Danmark, as they are well situated to really do some interesting things in the area, but I guess they were not interested.