Nadia I've had three different friends that I encouraged to join TSG back in December each ask me this same question since then. They had seen my posts about stats so knew it was possible to track formats but couldn't figure out how to do it. One person shared specifically that he was trying to choose "listening" in the status dropdown to set it to audiobook (I really thought I had posted about this at the time but can't find the post). I wonder if surfacing a "format" option to the main book page that would just arbitrarily pick an edition in the correct format would make this more discoverable, and having "editions" be more for making sure your specific ISBN/page count/etc is right as a next step if you care about that.