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.

Silicon Valley is the best place to start a tech company in so many ways.

We have just started, and if you compare the number of people using Skype to the number using a telephone network around the world, we're still just starting.

Today, over one million people now make their living on eBay, which is astounding.

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.

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.

If you want to be an entrepreneur, it's not a job, it's a lifestyle. It defines you. Forget about vacations, about going home at 6 pm - last thing at night you'll send emails, first thing in the morning you'll read emails, and you'll wake up in the middle of the night. But it's hugely rewarding as you're fulfilling something for yourself.