This site, which was announced in 2011 but launched in 2013, was originally developed by a consortium of 3 major US publishers (Simon & Schuster,Hachette, and Penguin) as a marketing tool. The site was intended to promote books, and it was chiefly know for its recommendation engine.
Bookish uses an algorithm that identifies recommended books based on similar characteristics. Unlike the NYPL's current recommendation system, which based its suggestions on the books that other readers were checking out, Bookish recommends books based on dozens of attributes, including a books' metadata, the awards it may have one, and so on.
So how well does it work? That I don't know for sure, but obviously it works well enough for the NYPL to offer a contract to Zola Books.
"Discovering great books on library shelves when I was a kid made me the huge reader I am today. To be able to partner with one of the best libraries in the world to offer the serendipity of book discovery online through Bookish Recommends is a tremendous thrill", said Joe Regal, CEO of Zola Books.
The new recommendation system is expected to be integrated into the NYPL catalog in the next few weeks. That catalog is supported by BiblioCommons, an independent tech firm that has contracts to support the catalogs of close to 70 public libraries, including ones in the US, Canada, and elsewhere.