How do you psychologically engineer a marketing campaign that you can’t pass up? If follow the methods of the past that have worked time-and-time again, then you can’t lose. Thirty years ago, Columbia Music House offered 12 CDs for a penny, and then you had to purchase a couple at a regular price. The regular price made up the difference in savings. It seems this model is being followed by this Audible ad which features a similar irresistible path.