I use TCL Rokus for all of the TVs in my multiple vacation rental units, because they're a great value and Guest Mode works amazingly well to secure my guests' accounts. However, I feel as if I refer a guest to the platform and they end up purchasing movies or premium subscriptions I have played an important part in the marketing funnel.
You should create some sort of affiliate program where owners of multiple properties earn a small commission on these type of purchases. This would help brand loyalty to the Roku platform as well as help generate sales as we can do direct marketing for these services in our guest communications.
Ideally, this would also include a suite of tools for remote management of all devices. I've had a lot of conversations with guests having to walk them through things such as resetting the TV that would be much easier with remote tools.