Skype Journal Editor Phil Wolff says his "rambunctious" December 2010 prediction for 2011 to be the year Skype passed 30 million concurrent users logged-in now seems conservative. Wolff predicted the company would "credit growth in the workplace and mobile devices with video-chat-ready cameras."
Skype's rapid growth comes just months after the service experienced its worst down-time in years right before Christmas, 2010. Never the less, Skype saw growth in the number of international calling minutes made last year that was more than double what every other phone company on earth combined saw. Perhaps because it's free between Skype users. Not everyone is a Skype user, however. Skype Journal now estimates there are about 177 million active Skype users around the world. That's a mere one third as many people as use Facebook, for example.
Skype isn't the only Voice Over IP option when calling outside the network at all. Experienced international caller and CEO of telephony startup MrNumber Jason Devitt, for example, recently discussed the pros and cons of a wide variety of alternatives in a discussion on Quora. Devitt advises that people who need to call one international number regularly should use Jajah or Rebtel because they are the cheapest. Numerous other competitors, including Google Voice, offer roughly similar services as well.