Your insurance broker has your telephone number, but your insurance broker doesn't have your Facebook ID. I think they are very different modes of communication. Commingling them can come with risk and peril.

My mom started an air-freight company; my grandmother built a golf course. I have a certain degree of entrepreneurial risk-taking in my family history. Maybe that eventually rubbed off on me a little bit.

Yes, I was a big math and computer geek, that's true. I was driven by the scholastic side of things. For me, it was all about what I could do with math and computers.

Dealing with ads is depressing. You don't make anyone's life better by making advertisements work better.

It's not 100 per cent clear to me what's working about Snapchat.

People want chat histories. They're a permanent testimony of a relationship.

For me specifically, it was important to graduate. In my family, I was one of the first graduates. My mom did not have a college degree. My dad did not have a college degree.

There's a certain degree of speculation that goes into valuations. In so far as the market supports a valuation, everyone who gets a great one deserves it, but they should also be cautious because that speculation is temporary. I saw Yahoo go from $100 billion to $10 billion. It's not a long-term measure.

Going public is 18-month process, while an acquisition is a 6-month process. Going public means going under so much scrutiny, regulatory approval, auditing, magnified 10 times. Having the stomach to do that isn't necessarily in my DNA. My DNA is building a product and a service.

WhatsApp will bring Facebook another billion users. We will be a billion-user product. Whether there is a direct valuation or an indirect valuation, there is value, and Facebook understands that well.

WhatsApp provides phone-number-based messaging, and people asked, 'Isn't that what SMS is?' Yes, but SMS is expensive, antiquated, and what WhatsApp did was modernize and level that playing field. For example, in Europe, if France wants to talk to Belgium, it's extraordinary costly because of border and telecom charges.

You have a certain identity that you present to the world on Facebook, and you have a certain identity that you present with the telephone, and they are different.