JACK DORSEY

The idea of Twitter started with me working in dispatch since I was 15 years old, where taxi cabs or firetrucks would broadcast where they were and what they were doing.

I think Twitter is the future of communications and Square will be the payment network.

People who are using it to sell things on Craigslist to holding garage sales - campaigns - the Obama campaign and the Romney campaign both used Square to raise funds.

I think Twitter is best when it sparks conversations elsewhere. To use YouTube and Facebook and all the tools we have available to us today to respond and also promote and answer and engage is awesome.

What's interesting about Twitter and the influencers that someone follows - like, say, Shaquille O'Neal - is that they see someone who is using the exact same tools that they have access to, and I think that inspires this hope to be able to really engage with someone like him.

I fell in love with flora of all types, especially ferns. Loved the sparse structure and repetition of shape - almost fractal.

I said a long time ago that Foursquare can make cities better. You have these augmented realities like Foursquare and Twitter and Facebook that provide these virtual nodes and instant feedback from anywhere, adding annotation around a physical places.

I loved couriers. You had this transfer of physical information happening throughout the city and the world. Someone picking up the package, putting it in a bag, going somewhere, taking it out of the bag, giving it to someone else. I thought that was so cool. I wanted to map it, to see that flow on a big screen.

You can follow your favorite company or organization. You can also mix that in with your family and your social network and talk about all these interests in real time. That's the value, not the brand 'Twitter.' Twitter just provides the venue for it.

Twitter was around communication and visualizing what was happening in the world in real-time. Square was allowing everyone to accept the form of payment people have in their pocket today, which is a credit card.

Twitter has been my life's work in many senses. It started with a fascination with cities and how they work, and what's going on in them right now.

It's a matter of invitations versus context. Twitter is really good at providing context, like, I'm having coffee at Third Rail Coffee.' Foursquare is about invitations to places. In this respect Foursquare has started to replace Yelp for me.

The first complaint we hear from everyone is: 'Why would I want to join this stupid useless thing and know what my brother's eating for lunch?' But that really misses the point because Twitter is fundamentally recipient-controlled - you choose to listen and you choose to leave. But you also choose what to put down and what to share.

When people come to Twitter and they want to express something in the world, the technology fades away. It's them writing a simple message and them knowing that people are going to see it.

A number of people in the United States, almost everyone, is using plastic cards to pay for things, but it's extremely difficult to accept these cards. So let's make it's easy and take more and more of the friction out as we can.

IM is interesting because you look at your buddy list and, at a glance, see what your friends are listening to, what they're working on, what they're doing. The problem was that you were bound to the computer keyboard.

I was fascinated with jeans, because you can impress your life upon the jeans you wear. The way you sit imprints on the jeans.

My goal is to simplify complexity. I just want to build stuff that really simplifies our base human interaction.

TweetDeck is a very interesting client, because it presents a view that no other client in the world presents, which is this multicolumn, massive amounts of information in one pane. And people really, really enjoy that.

The interesting products out on the Internet today are not building new technologies. They're combining technologies. Instagram, for instance: Photos plus geolocation plus filters. Foursquare: restaurant reviews plus check-ins plus geo.

There's an entire universe in every single tweet, and it all really depends on the content as far as how it's going to spread.

I'm less interested in how people are following each other and more interested in how they are following topics and tweets themselves. People are following more key words and concepts and more ideas and acting on those rather than individuals or organizations.

I am someone who tweets about what I have for breakfast, what I have for lunch, what I have for dinner, and for 99.99999 percent of the world, it's useless. It's meaningless. But for my mother, she loves it.

The Web provides a very easy way to immediately grasp what's going on. It really offers the transparency, so you can see, especially with the search engine, how people are using Twitter at one glance. The phone doesn't allow for that.

I love cities, and I love city governments in particular. But in politics it would have taken me 8 years from implementing a policy before I would get to see the feedback. With programming I could model the same policies and see the impact immediately. Technology is a far more efficient way to test.