Jabberbot's roster on Jabber.com is about 10 times the size of the next largest user's roster.� Whenever Jabberbot tries to log in now, it causes all kinds of server mayhem because every presence change causes the server to go read and parse rosters of everyone in Jabberbot's roster.� This, and the subsequent traffic backups, crash the server at Jabber.com
I don't mean to sound snotty, but: This demonstrates a performance/scalability issue with the server (not to mention an outright bug if it actually crashes), not a reason not to use presence for this purpose.
How large is that roster? If Jabber isn't scalable to this level, it may not yet be ready for widespread use. (Consider a mail server that crashed if you tried to send a message to more than 100 people at a time.) There is a very, very large degree of interest in the industry right now for exactly these sorts of IM bots.
�Jens
