The Verge: Facebook today began testing a new feature in its Messenger app that lets Canadian users call each other for free anywhere they have a Wi-Fi or cellular data connection. The test for now only applies to Messenger for iOS, but could roll out to Android users, as well as people worldwide, if the test goes well.
http://cdn11.mobilemag.com/...
Well I just stick to skype/viber. People who are logged online on those apps actually wouldn't mind being called. But on facebook they are probably busy.