Another differentiator is that Skype is free and simple to set up, and it costs us virtually nothing for a new user to join the Skype network, which is why we can offer the service for free.

When radio stations started playing music the record companies started suing radio stations. They thought now that people could listen to music for free, who would want to buy a record in a record shop? But I think we all agree that radio stations are good stuff.

Some Internet operators are concerned that video services such as Netflix and YouTube consume lots of the bandwidth on the network. While there is some truth to this, my guess is that the operators wished they could provide the same kind of services with the same success as Netflix and YouTube.

When a business becomes successful seemingly overnight, no one knows about all the months and years you've invested, all the projects you've tried before that didn't work.

With our work at Kazaa, we began seeing growing broadband connections and more powerful computers and more streaming multimedia, and we saw that the traditional way of communicating by phone no longer made a lot of sense.

Skype is easy enough to use so that people don't need to be tech savvy - a lot of users just want to communicate with their friends and family, and they find this is the easiest, cheapest way.

It is very similar to companies like Google and other internet companies. When you go and search on Google you don't pay for that. But sometimes you click on an advert and Google makes money on that.