VR monetization strategy across all platforms can be classified into 3 parts:
a) Transactional - Pay per view/download and in-app purchases
b) Subscription - Netflix/Spotify-esque platforms for VR content
c)Sponsored - Content monetized via brands and ads
Transactional is the go-to strategy for PC VR indie developers (Rift, Vive, PSVR) and has worked fairly well for top publishers. Premium content on these platforms will always be able to demand money upfront. We haven't seen a successful subscription VR content provider, but Steam (with HTC) recently announced plans around it.
Most viable monetization for mobile VR is going to be ad-supported. It is hard to imagine consumers willing to pay for each mobile VR experience they use. And it is even harder to imagine VR not being mass-adopted via smartphones. Going forward, Mobile VR promises immense scale to publishers, to rely primarily on ads for monetization.