If you use these to drive traffic to your site, why not mention the availability of a newsletter and position it as a value-add? Finally, consider offering subscribers the ability to choose what information they will receive by offering targeted, segmented communications.
This option places them in charge and provides you with detailed customer segmentation data. Every year, send a message that will enable subscribers to update their profile including contact info and preferences. The way to get the most out of e-mail is to segment your database and target content to those segments. E-mail makes this easy to do, especially because new subscribers can segment themselves.
These are only some of the e-mail address acquisition possibilities. We are sure there are many more that you can dream up that relate directly to your own industry. Remember, if your newsletter is difficult to find, let alone subscribe, you're only producing half the satisfaction you should and shortchanging your customers on some potentially valuable information. 2011 is the year of "leaping" head first into the e-mail marketing game.