The article states:
TeleGeography estimates that Skype's cross-border traffic grew approximately 41% in 2008, to 33 billion minutes --equivalent to 8% of combined international telephone + Skype traffic. 'Skype's traffic growth has been remarkable,' said TeleGeography analyst Stephan Beckert. 'Only five years after its launch, Skype has emerged as the largest provider of cross-border voice communications in the world.'
With dozens of international carriers, getting 8% marketshare is no small feat. To do so in just 5 years in a hyper-competitive environment is even more remarkable. VoIP has changed the communications landscape forever and for those that claim VoIP is dead, this is just more evidence to the contrary.