Comet for not-so-frequent events

Question

Is it worth using Comet for events that are not needed "in realtime", but with a possible delay of, say, 1 minute. Such would be:

• twitter status updates
• facebook updates

I know comet is perfect for a chat application (facebook and GTalk chats are using it), but does twitter, for example, use comet.

Or is AJAX-polling sufficient for such kinds of updates. Why I think it might be sufficient:

• with a poll-interval of 1 minute you are not putting too much load on the server with the ajax-requests
• "no new data" is not the predominant result, as in chat apps for instance.
• no server threads are held and so threads can be reused by multiple clients. Thus a thread pool of 100 threads may be used by 200 clients, whereas with comet it would be 100. (this is not true for my case, using Java - see this article that explains clever thread reuse)

(Note: with "comet" I denote the technique of holding the connection open. Some tend to refer to ajax-polling as comet as well, so I make that clarification - ajax-polling != comet in the above question)

Answer 1

It sounds like you have answered your own question pretty well :) Another thing to keep in mind is that you won't be filling your DOM up with <script> tags as with some long running comet solutions.

Answer 2

The problem with this question is that you seem to be just as qualified to answer as anyone. It's a trade-off one way or the other, and given that you don't tell exactly what you are making it's hard to say which is the lesser evil.