Now a days , Missed call marketing is getting popularity. In missed call marketing, people have to dial a specific number. Interesting point is that no call will be made actually as it will be disconnected automatically. So there is not cost involved for the user.
So your audience group will enjoy your content/service at free of cost actually. After they generate missed call, Boomcast will call them automatically with your desired content. Hence they will get your content just by placing a missed call.