It is really cool and useful. Interesting that you were able to gather enough data from users to make it work. I guess it was much less useful in the beginning?
I thought of making something similar with data from https://musicbrainz.org/
I thought of making something similar with data from https://musicbrainz.org/
Now that many millions of people have used it, I get a lot of great, often enthusiastic feedback on how Gnod makes the best recommendations.
That teached me that you can't convince people with just an idea. For most people, you have to deliver something which is already useful to them.