One thing you may want to try is sorting the classes based on "popular" or "trending" as those are more likely to have bigger groups. Another thing to try would be to join the ones that are featured on your homescreen and join the "sessions" where a group of people starts at the same time. You can see how many people are in a session before it starts.I use the video classes and like having a large here now leaderboard to spin with . Initially I tried Cody, Jenn and Christine's classes. Settled on Ally, as she always had larger groups. Is there anyone else that usually attracts a lot of users?