Jan Koum

On my iPhone 3GS, I use 'Instagram', 'Twitter' and 'Touch'.

We hear lots of stories where grandparents go to a store and buy a smartphone so they can keep in touch with kids and grandkids.

A lot of companies are global.

In some ways, you can think of end-to-end encryption as honoring what the past looked like.

We're somewhat lucky here in the United States, where we hope that the checks and balances hold out for many years to come and decades to come. But in a lot of countries, you don't have these checks and balances.

WhatsApp's extremely high user engagement and rapid growth are driven by the simple, powerful and instantaneous messaging capabilities we provide.

We're not interested in bombarding our users with, 'Hey, play this game, play this game, play this game.' It gets annoying, it gets in the way of messaging, and it gets in the way of staying in touch with people who are important to you.

I hate spam, and that's what happens when you let businesses onto the network.

It's important for people to have freedom to use whatever product they want. We have no problems with other people using other apps, so long as they keep using 'WhatsApp'.

We want to do one thing and do it really well. For us, that's communications between people who are friends and relatives.

If you look at firms like General Electric or other large companies, they don't just do one thing; they do many different things to generate sources of revenue.

'WhatsApp' began as a simple idea: ensuring that anyone could stay in touch with family and friends anywhere on the planet, without costs or gimmicks standing in the way.

I had so much fun in early days learning about networking, security, scalability and other geeky stuff.

Pavel Durov only knows how to copy great products like Facebook and 'WhatsApp'; he never had and will never have original ideas.

People appreciate a good product, a stable system. They want to communicate easily and use a product that just works.

Experiences from our youth shape what we do later in life.

Everybody who wants to join 'WhatsApp', we'll go out of our way to build a really awesome client for them.

In Russia, you really learn about a person.

As long as our user base continues to grow, at some point it will have critical mass, and at some point it will tip, and at some point, people will just have to use WhatsApp because their friends are using WhatsApp.

We continue to grow, and, just like with countries like China or other countries where we are not doing particularly well, we take a really long-term approach.

In some countries, WhatsApp is like oxygen.

We don't really talk about our future plans. But we, at the same time, try to build things that our users ask us for.

I have many regrets and things I wish I could go back and change, but I have also worked hard and tried to improve myself.

We're obsessed with making sure that voice and video work well even on low-end phones.

In terms of security and privacy, what people care about the most is the privacy of their messages.

We obviously try to be in tune with what our users want.

Everybody I meet who uses 'WhatsApp', I ask them a question: 'How did you hear about it?' And they say, 'My friends, my sister or my brother, somebody I know hounded me to install WhatsApp.' We think there is more power to the network when it grows organically.

The encryption genie is out of the bottle.

Clearly, you can't believe everything you read in the press.

The argument can be made: Maybe you want to trust the government, but you shouldn't because you don't know where things are going to go in the future.

We're not advertisement-driven, so we don't need personal databases.

People need to differentiate us from companies like Yahoo! and Facebook that collect your data and have it sitting on their servers. We want to know as little about our users as possible.

The F-word here is focus.

The difficult part for us is adding features without making the product more complicated.

I grew up in a society where everything you did was eavesdropped on, recorded, snitched on. I had friends when we were kids getting into trouble for telling anecdotes about Communist leaders.

When advertising is involved, you, the user, are the product.

When I was a kid trying to communicate with family in the Soviet Union, it was very difficult. You had to go through the long-distance phone companies like MCI, which were difficult to navigate and expensive to make calls through.

There were a lot of negatives, of course, but there were positives to living a life unfettered by possessions. It gave us the chance to focus on education, which was very important in the Soviet Union.

I grew up in a country where advertising doesn't exist.

A lot of what I experienced growing up in the U.S.S.R. and coming to the U.S. as an immigrant actually reflects itself in Whatsapp. Experiences from our youth shape what we do later in life.

I grew up in a country where I remember my parents not being able to have a conversation on the phone. The walls had ears, and you couldn't speak freely.

No one wakes up excited to see more advertising, no one goes to sleep thinking about the ads they'll see tomorrow.

Facebook, Google, Apple, Yahoo - there's a common theme. None of these companies ever sold. By staying independent, they were able to build a great company.

Our phones are so intimately connected to us, to our lives. Putting advertising on a device like that is a bad idea. You don't want to be interrupted by ads when you're chatting with your loved ones.

I didn't have a computer until I was 19 - but I did have an abacus.

Ironically, I grew up watching Indian movies as a kid in Russia. I am quite familiar with Bollywood. I grew up watching 'Disco Dancer;' I watched it some 20 times as a kid.

I only have one idea, that is WhatsApp, and I am going to continue to focus on that. I have no plans to build any other ideas.

Marketing and press kicks up dust. It gets in your eye, and then you're not focusing on the product.

Nobody should have the right to eavesdrop, or you become a totalitarian state - the kind of state I escaped as a kid to come to this country where you have democracy and freedom of speech.

A lot of times, people start out with a lot of good ideas, but then they don't execute. They lose the purity of their vision. You end up running around in circles.