Here are some links to articles that tell you how to create and promote your own email-based mailing lists. In fact, the two are really just alternative forms of interactive publishing. So can a Web site, which can have interactive discussion groups. We've found that they're both excellent ways to build traffic to our site. And since we're an ad-supported resource, traffic is the name of the game.
Mailing lists are also valuable advertising vehicles in their own right.
Starting your own mailing list is one of the best things you can do to boost traffic to your Web site, but it isn't the easiest thing in the world to do. The most popular mailing list software packages are Majordomo, Listserv and Lyris. All are quite powerful and well supported, but none are particularly easy to use. If you want to run your own mailing list, you'll need someone geeky on your staff who can figure out how to get things up and running with a minimum of hassle. Also, mailing lists require a certain amount of ongoing maintenance, so you'll need to have a staff member available for that, although once things are set up, not that much technical expertise is required.