Like WhatsApp, Viber is free to use and has no advertising model. If they are not making money off me directly i have to wonder how safe my data actually is with this service.
WhatsApp is not free to use. iOS users are charged a flat 99c fee while Android users are charged 1$ a year from the second year onwards.
I do not know how secure Viber is but they have been steadilu acquiring good user base. If I was Viber, I would cash on this opportunity to write a blog or advertise their security models.
