I think for this to be successful you need to encourage users to server the videos. There are a couple things that might help this: - Popularity could be based not only on views, but how many total minutes of the video were shared by other people. - When someone watches a video, they have to keep hosting it until they share as much as they've watched it (so if they watched 10 minutes, they have to share it until they…
Plenty of users would store popular videos to chase after premiums, but it will be similarly profitable for a handful or so of people to host the less popular videos because there will be less competition for views (which are in turn modulated by the amount of data for a video you contributed to a given P2P stream).
This solves the problem of obscure but useful content being phased out.