Well in the post he writes:
LibraryThing has a bit of a cult following, and once you've used the site it's easy to understand why. For those with a great many books, it's nice to be able to easily check if you have this book or that.
Now, less than a week later, I just had my first case of using Library Thing to easily check if I had a book. I had received a request from an academic journal to do a peer review of a paper submission focusing on a famous book on dream and Christianity. Starting to read the paper, I realized I really should have a copy of that in front of me as I went through the arguments. Do I have to go to the college library to get the book or do I have my own copy at the house? I think I have it, but it is so frustrating looking through the spines of books and never finding what I am looking for. When I don't find a book I had thought I might have, I am never sure if I have been to hasty and overlooked the book or actually don't have it. Hmmm, Library Thing would know if I have it ... and yes, I do! So then I searched my shelves with confidence that I was looking for something that was actually going to be there. (And found it.)
Thank you, Hills of the North, for mentioning Library Thing in your email and writing the post about it on your blog.