Good job shipping. That said: I use Goodreads for this. One big feature it provides for me is community curation, so it would be difficult for another service

Good job shipping. That said: I use Goodreads for this. One big feature it provides for me is community curation, so it would be difficult for another service to usurp it at this point. My Goodreads account is also tracking 789 books - well past the breaking point of the GUI paradigm you're pursuing. A timeline is not really suited to administration either. If you want to add a timeline for visualization, restrict it to visualization, then make it compact enough to accommodate more than one title per week across years of use.