The conclusion that this app gives voice/video chat possibillities to the "more then one billion" facebook members is really far fetched.
First of all, I do not believe, that there are actually that many people on facebook. Accounts, yes, but people? We run and maintain alone for our products and apps 140 individual FB accounts, there are 20 guys and girls working here, 2 have a personal facebook account. I know companies that run thousends of accounts. Hardly of any interest to the individual.
Secondly, this app allows only access or calls to other iOS users and they need to have the app installed and running. That narrows it down quite a bit I think. Also, they have to have US accounts, taking out 80% of all accounts.
So, this feature runs directly against facetime, preinstalled on all iOS devices and always working, iMessage, preinstalled and always working. How many iPhones have the facebook app installed?
Having skype (on 88% of all iOS devices) text, calls and video chat is availabe over any platform not restricted to iOS AND it works to POTS.
What is the killer feature with this app? That its from facebook?