I might be missing the big picture, but wouldn't log-in with oauth[0] solve integration problem and removed impediment from new users coming in? Also, if you do not mind, which algo do you use to find matches?
[0] https://en.m.wikipedia.org/wiki/List_of_OAuth_providers
Edit: formatting
The algorithm uses a simple item-based neighborhood model. i.e. if you like song A, Findka looks up all the content liked by other users who liked song A and probabilistically chooses an item that was well-liked. To help the algorithm keep learning, 35% of the recommendations are purely random ("epsilon-greedy"). I describe the implementation here[0], though it's changed slightly (now I export the database every day or so and generate a model on my laptop, then I load it into memory on the server). I experimented with a machine learning-based model (a latent factor model) last week, but it seems I don't yet have enough rating data for that to be useful.