What is Viber?
Viber is an application for iPhone®, Android™, Windows Phone and Blackberry phones that lets you make free phone calls to anyone that also has the application installed.
When you use Viber, calls and text messages to any other Viber user are free, and the sound quality is much better than a regular call. You can call or text any Viber user, anywhere in the world, for free. All Viber features are 100% FREE and do not require any additional “in application” purchase.
How Viber makes money?
This is a representative of Viber.
For now, Viber’s focus is on adding platforms, adding features and integrating with more and more platforms, and improving overall system performance. At the same time, we are working on additional future premium services that will generate revenues. The basic Viber service – Viber to Viber phone calls and text messages – will ALWAYS be free.
So in other words – we have the same model as you described, but it will simply come to reality in the future.