Open Graph is a language for structuring content and sharing that goes on in other apps, and we're continuing to build it out longer term. But we found we need to build more specific experiences around categories like music or movies. Where we've taken the time to build those specific experiences, stuff has gone quite well.

When we are thinking about stuff like embeds, we are not thinking about how we are competing with YouTube. We are thinking about how are we going to make it more useful for people to share stuff on Facebook.

So I think that the scale of the systems has created this responsibility for us, where we have to be more proactive about finding and addressing issues [harmful content]. And we can do that both by building technology that is possible now, but wasn't even possible five or ten years ago, and by hiring people at a scale that would not have been possible for us before.

Facebook is shaping a broader web. If you look back for the past five or seven years, the story about social networking has really been about getting people connected. But if you look forward for the next five years, I think that the story people are going to remember five years from now isn't how this one site was built; it is how every single service that you use is now going to be better with your friends.

When I'm introspective about the last few years I think the biggest mistake that we made, as a company, is betting too much on HTML5 as opposed to native... because it just wasn't there. And it's not that HTML5 is bad. I'm actually, on long-term, really excited about it. One of the things that's interesting is we actually have more people on a daily basis using mobile Web Facebook than we have using our iOS or Android apps combined. So mobile Web is a big thing for us.

Facebook originally got started around the same time as a bunch of the early smartphones and those platforms got started. So we didn't really get to play any role in developing that platform.