I have a hub with method that is called client-side. This method launches a timer with a delegate that runs every 10 seconds. Since it wouldn\'t make sense to keep running t
From http://forums.asp.net/t/1829432.aspx/1?How+do+I+get+list+of+connected+clients+on+signalr+
IHubContext context = GlobalHost.ConnectionManager.GetHubContext();
context.Clients.notify("Hello world");
So you should be able to get context.Clients.Count.
That post also references the wiki which has lots of good info. You could try using the OnConnected/OnDisconnected examples to track the users, and when you get to zero users stop your call.