The iAudioCampus product line includes the digital audio version of industry and professional certification textbooks and other related course materials, as well as a related “Study Guide”, which includes all charts, graphs and other non-verbal materials. There are no hard goods that need to be inventoried. You may download the materials on to one of many digital audio devices including the iPod, MP3 and CD players. There is no inventory, no shipping and handling, just a couple of clicks of a mouse and you can access the materials.