What do you do when your aging email database stops being productive? Do you scrap the whole thing and start over from scratch? Do you abandon email marketing all together? Maybe you simply change tactics and put that old list to work in new ways to increase your sales.

According to a case study from MarketingSherpa, The Motley Fool was in just such a predicament. Its opt-in email list was 8 years old and wasn't performing the way it used to. Faced with the challenge of what to do, the email management team tossed around several ideas and decided to change the way in which the email list was built.

The previous system was based on a double opt-in system which required interested parties to respond to the initial membership email in order to secure a spot on the list. You've seen these lists before. In fact, most companies use a double opt-in system. If you've ever signed up for something and had to confirm your email address by clicking a link in the first email message, you've double opted-in.

The Motley Fool decided to change their system to single opt-in. In the new system, simply entering an email address signed users up for the mailing list. But with single opt-in comes the increased chance of bogus or incorrectly entered email address. The Motley Fool instituted several safeguards to keep their list fresh and reduce the number of bad email addresses.

The result? Conversion decreased but overall sales increased by 45% when compared to the old system. And as the Director of The Motley Fool's Email Management said, sales are what mattered. In addition, their marketing list grew by 130% since the single opt-in system was implemented.

Most companies play it safe and follow the herd. But The Motley Fool took a chance and, after some testing, took the minority approach to their email list. And it paid off for them. Keep that in mind when you're working on any kind of marketing campaign. Following established norms may be safe, but sometimes the benefit of taking a chance greatly outweighs the downfalls.