That's the number of people who have skype running on their computers, not the number who are on a call. Skype is fairly common, automatically starts when the c

That's the number of people who have skype running on their computers, not the number who are on a call. Skype is fairly common, automatically starts when the computer starts, and doesn't actually close when you click the "x". So I think that number is believable for total users online worldwide.