What’s the best way to reactivate your churned customers?

Jason Fried (Co-Founder & CEO at Basecamp)
Marketing Without Marketing: Why 37Signals Favors Customer Retention | Inc.com

The way I see it, I can spend a lot of time and money trying to persuade a bunch of newcomers to try Basecamp. Or I can spend a lot less effort helping current customers get more out of something they’ve already purchased and enjoy using.