I can see the benefit of Comet in this case but I don't see the benefit of Flash. Please could you explain.
I thought like Comet, Flash can send data asynchronously. the client doesn't have to continually poll the server. Am I wrong?
Yep. Thats correct. Although, at the last point I looked into it, there were some firewall-related problems with using Flash for that purpose. I don't remember the details though...