The ClickZ Guide to Email Marketing sat waiting for me in my real-world mailbox last night. I had almost forgotten it was coming, probably because I didn't pay anything to receive it.
Free stuff is cool.
Actually, it's not quite free. It will cost you about five minutes of your time to fill out a variety of questions about your job and preferences. ClickZ provides the free guide as an incentive to gather demographic information on their audience. Offer a free and valuable resource to those of your subscribers who take the time to fill out a survey, questionnaire, or something similar. The guide itself features a whole slew of articles that have run on the ClickZ site in the past.