Google chat couldn't exist without Comet, (unless they redid the entire thing in Flash and please don't get me started on the whole Flash/Silverlight mess) A l

Google chat couldn't exist without Comet, (unless they redid the entire thing in Flash and please don't get me started on the whole Flash/Silverlight mess) A lot of tech decisions don't deliver 10x improvement in the value-add for you users, but even a 10% value-add can be a powerful differentiator in a competitive market. And finally Comet isn't really a significant technological hurdle. Implementing it versus simple AJAX isn't a very big increase in your tech efforts and might be very much worthwhile. I'm not saying you should use Coment in all your future web dev, this isn't fanboism. Just spend an hour or two to get a rudimentary understanding of the technology its costs & benefits so you can decide for yourself if it is a good fit for your next project.