If you look at companies with upside potential, Twitter's right there. They've established a brand in a world where it's extremely difficult to establish a brand. It's a global brand, people recognize it, people want to let you know what their Twitter handles are, etc.

I'm very, very bullish about our prospects, and as I tell our board, as I tell our employees, this is the time to invest. There's so much opportunity. Let's just invest in that opportunity, and really get after it.

I think there are lots of opportunities to improve the product. When you read the press, people say, "Oh, the product needs improvement." I look at that and say, "Hey, that's an exciting thing to get behind!" Because they can improve that product. That leaves more upside from an innovation and revenue potential than you're gonna find in a lot of places. So you could say that's a downside, I see that as an opportunity.

Only our company and a handful of others are poised to write the future.

I think it would be absolutely reckless and irresponsible for anyone to try and break up Microsoft.

What we've gone through in the last several years has caused some people to question 'Can we trust Microsoft?' .

I meet with Satya [Nadella] what probably amounts to four or five times a year - either to brainstorm something or just as a shareholder, we'll sit down and chat. That's always quite helpful for me and hopefully him in terms of thinking things through. I still have a number of friends and colleagues who occasionally want to brainstorm or chat about something, and that's always fun.