I have written a guest blog post with a comparison of the two sites for authors. The post covers my experience of meeting readers, giving away books, and gaining reviews. Both are really good sites for readers and authors and are a helpful point of connection between the two. If you haven’t yet had a look, I would highly recommend them. Goodreads has a lot of groups and interesting discussions and LibraryThing is full of readers who are wanting to review books and interact with authors. The site has a fascinating zeitgeist page of reader and book statistics, if you like that kind of thing. I love finding out about which books are popular and which languages are the most translated. I have met some interesting people on both sites and will continue to interact through discussions and groups.
If you would like to link up with me on Goodreads I would be happy to see you there. I also have an author profile on LibraryThing but you don’t connect in the way that you can on Goodreads. Do have a look, if you are interested and browse around the site.