“Tastemates”: somewhere out there is someone who likes all the same [books/movies/music etc] as you. 

Have an algorithm find that person and surface the things they love that you haven’t discovered yet.

Makes the recommendations more trustworthy.

Crypto/web3. Author of Read Write Own

readwriteown.com

This is pretty much what google discover (content recommendations in the google app) does generalized to more than one tastemate. Started with articles but also longer form content, podcasts, videos etc. 

It’s also what Netflix, good reads, Spotify all do on a more local basis.