Subject lines are as important to e-mail as headlines are to advertisements and letters. Successful direct marketers--those who measure their success by the amount of goods sold--often spend up to half of the time they invest in a project on the headline.

If your e-mail subject lines fail to offer a benefit, your e-mail is likely to go unread- -or be immediately deleted. When sending a newsletter, for example, don't use a subject line that says: "My July Newsletter." Instead, describe the benefit that your readers will enjoy when they read your newsletter, i.e., "6 reasons 1 page newsletters are better than 4 page newsletters."