If someone told you there was an easy, quick and ridiculously inexpensive way to reach members of your target audience in their own home or workplace, you'd probably expect to hear the alarm clock ring at any moment to wake you from your dream.
Response rates are good because people who are interested in a subject request the ezine.
Too, that invited information ends up right in their inbox, which makes it far easier to read than, for instance, a Web forum or newsgroup, which must be visited. Although there are sophisticated email programs that personalize each message and follow up automatically, establishing an effective ezine is surprisingly easy. DO keep your paragraphs short. Four sentences per paragraph is usually maximum, so that people have a place for their eyes to rest. DO double-space between paragraphs.