As soon as our library system introduced Bibliocommons in 2011, I created an account; I got excited at the thought of creating lists, keeping better tabs on my holds & checkouts, and simply working with a more interactive, user-friendly interface. I'll admit that the novelty wore off *fairly* quickly on a personal front, but I still enjoy creating and sharing lists along with several other colleagues via Moncton Public Library's account. Any lists that catch your eye? Guess which ones are my favourite (hint: OM NOM).
These days, I'm much more apt to check in on my Goodreads account; I have more people to interact with, and I prefer the interface and usability. I stumble upon some great treasures while browsing Goodreads, ie by seeing what my friends & colleagues are reading, so much so that my "to-read" list is becoming daunting. The only con of Goodreads VS Bibliocommons is that if ever a title interests me, I need to double-check if we have it in our catalogue (due to mountain of books currently residing in my home, I rarely buy books nowadays).
Are you on Goodreads? Add me :)