Audia, formerly whisper.fm, was a start-up that I worked on with George Ruan and Sam Kaufman. It was a very simple idea. Instead of downloading a podcast, you could call in and listen to it over the audio channel of the phone. It enabled you to get podcast content without a data plan. If the connection got cut off then when you called back it would pick up where you left off. There were several different numbers depending on what you wanted to listen to. Of all the start ups that I’ve been involved with, this was (so far) the only one that ever had a paying customer! We also had it working in multiple languages.
A screen shot of the backend analytics for who was listening to the podcasts