The advantages are:

That the system is highly encrypted to protect your privacy.
Low to now cost for international calling even from landlines.
Versatility with communication methods since the crypto currency is adaptable to any communication technology that includes the wallet software and everything.
Skype does not have a secure payment system, Vior does.
Privacy is retained even through registration processes.
Account phishing is extremely harder due to the encryption.


There are many more and I'm not going to go into the offset tech of Coinville.