As many users as Facebook, many of those users have entered their payment details, a great brand that is just as big as Facebook, and synonymous around the world with communication. I just happen to be talking to a non-tech computer user on the weekend who told me that he and his entire family and friends overseas do not use Facebook because Skype does everything they need in terms of staying in touch and it has work…
> "As many users as Facebook" I suspect that there is a closer correlation to one account = one person with Skype than Facebook since there is little social incentive to create multiple Skype accounts. In addition, the strength of relationships between Skype customers is more easily determined. Finally, Skype has the potential to scale well into MicroSoft's core B2B business model.
http://news.ycombinator.com/item?id=2532230
Facebook has 3x active over Skype - but as you mention, while Facebook are straight-up about their numbers, it is still hard to compare because of differing methodologies and different app types