Pssst! Book recommendations from LibraryThing

I just launched the new "Pssst!" feature, which examines your catalog against patterns in the catalogs of LibraryThing's other 30,000 users to produce book recommendations just for you. LibraryThing already suggested books on a book-by-book basis, and matched you up with users who had similar libraries. This completes the circle.

To use the feature you need to have cataloged ten books. If you have, check our your recommendations. If you haven't, check out my recommendations—ancient civilization and web design, it got me. (Incidentally, yes I have read Thucydides. I just have another 2,000 books to catalog!)

Recommendations are available in three types:

• People with your books also have…
• Similarly-tagged books
• Most popular books you don't have

In each case, I've divided the recommendations into "fiction" and "non-fiction" (a rough, algorithmically-determined label). You can click a link to exclude books by authors already in your collection, so a mystery buff doesn't get showered with minor Agatha Christie novels.

Needless to say, the point is not commercial. Although you can find commercial links, I didn't add any to the recommendations page. I hope you'll agree that LibraryThing—with no funding and building on a real community—produces recommendations as good or better than the ones you're getting from Amazon, and ones not tilted toward current offerings or what you bought last week.* Community beats commerce, even in commerce.

Let me know what you think here, or discuss it at length on the Google Group.

The back story:

Long-time users may remember a previous feature that also produced book recommendations. I took it down because the math was so complex that it was slowing the site down, even when I required people to wait 20 minutes for the results. This new algorithm is much faster, relying on the existing book-by-book recommendations. (Book recommendations are regenerated on a sliding schedule, at night.) The old feature was also made before the "works system," so it threw up a lot of books already in your catalog. Even so, I want to bring back suggestions focused on most-similar users, if I can do it in a way that doesn't kill the server.

I agonized over the name—Recommendations? Suggestions? I even contemplated "Pimp a Book" (I own the domain). "Pssst!" sounds a little gimmicky, a little "marketing-ish," too "Pssst!®." The deciding factor was length. I wanted to give it its own tab—it's a major feature already, and I have plans to expand it. The other options were just too long.

Lastly, I want or plan to extend the feature in the following ways:

• A way to mark what you think of the recommendation—good, bad, totally off-the-wall.
• A way to add a book to your wish list.
• Tracking the list over time, so you could find out the "new" recommendations.
  
• A "why" button. (For example: "Suggested because you own The Hobbit and Sexing the Cherry.") That's very expensive to do for all books at a time. One-by-one, I could "Ajax" the answer in, but so much Ajaxing—people will click "why," "why," "why" like mad—makes me nervous.

Oh, I renamed "extras" to "Tools and Toys." I'll be adding to that tab quite a bit in the coming weeks. Have the cool toys—chicklets, Thingamabrarians, that nifty LibraryThing-Outlook-PDA conversions, etc.—never made it off the blog or Google Group.

*I mourn the fact that my Amazon recommendations have flipped, from obscure Throwing Muses albums (of course, I have all of them, but Amazon don't know that), to baby-care books. O for lost youth!