Skype has 663 million "accounts", very few of these were active.
According to http://www.statisticbrain.com/skype-statistics/, only 31 million Skype users are active as of 2012.
According to http://www.statisticbrain.com/skype-statistics/, only 31 million Skype users are active as of 2012.
FWIW, I don't know anyone (across 5 countries of friends and business partners) who doesn't use Skype.
Still, wouldn't that amount to more than 30M users?