Whatsapp Finally Launched Free Calls

As we can see, whatsapp is now offering free voice calls, and quality is 100% better then normal calls.

How do you guys compare it with other apps that were already offering same feature (Viber, Line, Facebook Messenger, and etc).

Considering that whatsapp is basically a paid application, its $0.99 a year after the first free year.

I also think that it may cause some loss to mobile operators as we can almost call without any worry's of cost on whatsapp, on a simple 1GB package plan of 3G/4G or on WIFI.