Account Updater is the easiest way to keep your subscriber’s credit cards up to date. But if you can’t get the technology (only a few merchants supply it, and even then it’s difficult to get), then the second-best tactic is to have subscribers update their credit cards on your site. After all, it’s easier to get a member to do something while on your site than to pull them to your site through an email. (Although you should keep sending those email reminders, too.)
Below we took a screenshot of Aweber’s reminder, which was displayed at the top of the page when a subscriber logged in. Note this shouldn’t be a lightbox overlay (or pop-over) that subscribers can “X” out of and ignore, nor should it prevent the subscriber from using the site as intended. It should just be a constant reminder in great site real estate, cued a few months before expiration.