People interact with their phones very differently than they do with their PCs and I think that when you design from the ground up with mobile in mind, you create a very different product than going the other way.

Every startup should address a real and demonstrated need in the world. If you build a solution to a problem lots of people have, it's so easy to sell your product to the world.

I actually think some of my best moments in life have been while I was with people from Instagram - whether it's super late nights getting a release out or being able to travel to places I'd never visited and meeting some of the most interesting people I've ever met.

If you've got an idea, start today. There's no better time than now to get going.

The best feature is less features.

I was never as focused in math, science, computer science, etcetera, as the people who were best at it. I wanted to create amazing screensavers that did beautiful visualizations of music. It's like, "Oh, I have to learn computer science to do that."

Obviously, being the CEO, there are a lot of eyes on what you do and what you post and how you post, and I think one of the challenges of Instagram in general is that, as we get bigger, there are just more voices in the room, more eyes on everyone's accounts.