I will not reproduce the whole article (read it, quite interesting!), but made a graph with the data:
Nice, Skype in the first position!
- They say 9 million households use VoIP
- This means more then 9 million persons
- My guess: 2.5 persons per household (?)
- 2.2 million Skype Households in the USA
- Therefore about 5.5 million Skype Users in the USA?