When a company offers a package with set usages they do so knowing that almost all clients will use less.  Otherwise the offering would lose money and make no profit.  In VoIP this comes in the form of unlimited minutes.  Nibble Netwrx have chosen to go a different way.  We pass along the usage costs to the client based on their individual consumption.  Many are fearful of the usage cost as an unknown varying rate but in our 16 years of experience this is always a benefit and never a burden.  Reach out to Nibble Netwrx and let us discuss your telephony business details.