The Aflac Duck is a rock star in Japan. That’s the only way I can describe how big he has become there. In a down economy, Aflac Japan’s sales increased by 12% in 2003, the year we introduced the duck. Today we insure one out of every four Japanese households and are the leading insurance company measured by number of policies in force. We took that title from Nippon Life, which had held it for more than 100 years.

A version of this article appeared in the January–February 2010 issue of Harvard Business Review.