I missed this when you posted, but I'd love for you to check out Hardcover! (
https://hardcover.app/ ).
We do exactly what you described - recommending books based on collaborative filtering and comparing your tastes with similar readers. There are a few ways we make this available:
• We calculate a "match score" from 0% to 100% for you with each book that we can. A score of 100% means we're pretty sure you'll rate it 5 out of 5. An 80% means we think you'll rate it 4 out of 5. We show this score throughout the site. This is similar to Netflix's match score (but a lot more basic ). I've found it's a lot of fun to follow people, then see this score next to books people are interacting with. That combination can lead to finding some gems.
• On the "Recommendations" page we show you the books that have the highest match score for you. You can filter the books on this page by popularity. Books with more readers means the Match Score will be more accurate.
• On every books page, we show "ratings by similar readers" and "reviews by similar readers". This gives you a quick way to see what other readers with similar taste think of each book.
• We have a Readers Page to find which readers have the closest taste to you. You can follow them if you want to see what they're reading.
We have all the same tracking you'd expect from GR/SG - tracking what you read, dates, stats, a feed of friend activity, private/followers-only books (in case you want to not have everything public) and a lot more.
If you join, I invite you to jump on our Discord and say hi!
Adam
https://hardcover.app/@adam