I certainly agree that an online algorithm will be much preferable to something that depends on large one-off runs.
It seems like you should also gather data from other users. Maybe a netflix like recommendation engine (https://github.com/Sam-Serpoosh/netflix_recommendation_system). That way it would be like an implicit follow. If someone has a similar engagement profile to you, you will be recommended content that they like.
All in all, it sounds like you know what you're doing and I'm excited to follow along for your updates.
RE: [Programming] Beginning the Search for Discovery