So what gets used by the folks in VOIP land ? Does Skype have as many users as it says?? Vonage has had an IPO ready to go from day one and the investors may not be getting out with much of a gain. The whole of the VOIP revolution is due to the useless email world. At one point email uses counted now they have been rendered useless. An attack on chat , email, bulletin boards, and other forms of mass user communications have been attacked leaving VOIP as the standing method that has not been attacked. So when the attack happens this form of communication will fade in importance as others have before them. At the core is the human engineering problem of having un-welcomed attacks challenge the agreeable user base that wants to talk or communicate with each other. The unmeasurable aspects of the convergence of Moore's Law and Metcalfe's Law with the Exploitative Barbarian Attack Law and if the technology survives the EBA assault it will be subjected to the Obesity Bueartic Attack and displaced by a disruptive technology starting the process over again.

Moore's Law, which states that computer processing power doubles every 18 months at the same price point.
Metcalfe's Law, which states that the value of any network increases exponentially with the number of users.

Exploitative Barbarian Attack Law, which states that as a disruptive technology displaces a traditional technology with an established governance model the growth of illegal attacks expands till it renders the advantages of the disruptive technology worthless.

Exploitive Bureaucratic Obesity Attack Law, which states that as a disruptive technology survives EBA and becomes bankrupt the regulatory stabilization will render it useless if a disruptive technology emerges.

By comparing the traditional implementations expansion and it eventual governance instances one can determine the speed at which its disruptive counterpart will become useless. Email can be compared to US postal services prior to regulations and standards implemented during 1800's. The difference and why this is caused the Exploitative Barbarian Attack Law is that the ability for EBA has increased without the ability of regulatory entities to enforce and protect its users. Therefore the Metcalf law needs to have caveats that define the value, are the users intended purposes the value?
The EBA will expand to consume the monetary advantage provided by the innovative disruptive technology. The rate of expansion of the EBA can be determined by measuring the traditional technologies cost to regulate based on the cost of regulation for unit of service. Further more the disruptive technology will prove to be bankrupt prior to implementation of a regulatory regime. The cost to implement a US Postal network was daunting and the cost to maintain it monopoly finally collapsed the viability of this service offering. The US Postal service was displaced by email, cheaper competitive carriers, and entrenched bureaucratic obesity. Prior to this bureaucratic obesity the mails where subject to EBA rendering the viability of any postal communications useless. The now bankrupt system was recovered from its failure to provide regulatory oversight and relaunched in a monopoly controlled by the state. So any communication service or transfer of information is attacked by barbarians and bureaucratic obesity. I suggest that the attacks lie at either end of the lifetime of any service forming a bell shaped curve and the time is reduced by the convergence of Moores law and Metcalfes law