But when a mailing list gets a lot of traffic, and especially when it develops several different threads of conversation simultaneously, it gets very difficult to keep track of it all. For this reason it's rare to see more than two or three active threads in a mailing list. On the other hand, on a good conferencing system, a single conference can easily support dozens of active topics. E-mail also puts more of a burden on individual users, who have to sort, file, or delete all the messages. I find this to be a pain even with a good e-mail program like Eudora, which can automate some of the sorting and filing.
Mailing lists show another drawback when it comes to supporting fast-paced discussions.
There is an inherent time lag in broadcasting e-mail messages, sometimes measured in hours. If someone asks a question, several people might answer it, not realizing that they are duplicating efforts. But in a conferencing system that resides at a central location, everyone reading a topic can be sure they are seeing everything that has been written up to this very moment. In a very active topic, it's still possible for another response to slip in while you're composing your own, but it's much less of a problem because the only delay is the amount of time it takes you to type your response. I should note that we seem to be using e-mail fairly effectively for this discussion, so it does have its uses.