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.

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.

When we started Skype, if you look at analyst reports, no one forecasted it as a big business. Also when Google started, it was not fashionable to be in search. It's not trying to do the obvious - that's the hard part.

Today as an entrepreneur you have more options.

If you can use a Web browser, you can use Skype.

You have 1 billion people using the Internet with 200 million of those now using broadband internet connections, so the Internet has become a powerful network. It can carry calls.

When we look at investing, we always think about 'how defensible is this, how likely is it that somebody is going to copy this.' E-commerce tends to be something easy to copy because it's execution.