Evan Spiegel dropped out of Stanford University in 2012, three classes shy of graduation, to move back to his father’s house and work on Snapchat.

Spiegel’s fast-growing mobile app lets users send photos, videos and messages that disappear a few seconds after they are received. Founded in 2011, Snapchat is especially popular with teenagers and young adults, but many parents fear the app is the ideal tool for sharing lewd photos, or “sexting.” In spite of the unfavorable baggage and no revenue, Snapchat is growing. The company has raised about $70 million in venture funding from investors such as Institutional Venture Partners and Benchmark Capital. The Pew Research Center found in a recent poll that 9 percent of American cell phone owners use Snapchat.

Spiegel’s ideas about the permanence of digital data run counter to those of just about everyone else in the industry. “It would be better for everyone if we deleted everything by default and saved the things that are important to us,” he says. “Right now most businesses are built on saving everything and then writing a ton of software to organize it and hopefully find the things that are important later.”

The company recently added a feature called “Stories,” which lets snaps live for 24 hours.

Speigel, 23, talked with The Associated Press about his app, and his plans for the company’s future. The interview has been condensed and edited for clarity.

Q: The first thing many people think about Snapchat is its use for sexting. How do you address that?

A: The fun thing about Snapchat is really the surprise and the joy that comes from learning how to use it. But it was tough in the beginning. I can even remember when we were first trying to get people to get on the service, I stood on the (Santa Monica) promenade and I would go up to people and be like: “Hey, you should try this application. You can send

disappearing photos.” And they would say: “Oh for sexting,” which kind of meant that we had to do a better job teaching people. And we’re fine in how we described the service over time. Now, the growth of the service shows that it’s about a lot more.

Q: What’s the point of Snapchat?

A: It’s fun. Period. And that’s the most important part. Somewhere along the way when we were building social media products we forgot the reason we like to communicate with our friends is because it’s fun. People started conceiving of their friends as networking tools, like ‘friend me so you can be friends with someone else’ or ‘the more people you know, the more networked you are.’ But we see real value in having a fun conversation with your friends.

Q: How did you come up with the idea?

A: A buddy of mine was bummed about a photo he (regretted sending). And so we started looking at some of the other applications in the space that were doing disappearing texts, photo, video. And they really had a hard time because there was a lot of stigma around deleting things. But when Bobby (Bobby Murphy, Snapchat chief technology officer and co-founder) and I built the prototype and started using it, we realized how much fun we were having sending the photos back and forth.

And based on our experience with the application we were able to do a good job describing how ephemeral content can make an experience that is really fun, exciting and way more engaging.

Q: Would the service be as popular without the disappearing aspect?

A: This is something we like to ponder as well. One of the greatest benefits of the service, especially in the early days, was that it was 10 times faster than an MMS (multimedia messaging service) message. So a lot of people just liked it because the interface was so simple. It sent the photos so quickly.

It was a lot faster than opening up a text message, going and taking a picture or choosing it from the gallery, uploading it –which took a really, really long time – and then sending it to your friend. There are lots of different benefits to the Snapchat application. Obviously we haven’t yet run the experiment of making the messages permanent but we have seen that people save messages they receive. Two percent of snaps that are received are screenshot (and saved). So there’s obviously a lot of value to sending images quickly and if an image grabs you, or you think it’s interesting or fun, it’s always fine to save it.

Q: How’d you go about getting your first round of funding?

A: This guy named Jeremy Liew, who works at Lightspeed Ventures, one of his partners, Barry Eggers had a daughter who was using Snapchat. She said her three favorite apps of the world that everyone was using at her high school were Angry Birds, Instagram and Snapchat.

And (Liew and Eggers) had never heard of Snapchat, so they were like we’ve got to find those guys. So Jeremy sent me a Facebook message. I ended up meeting with him and showed him some of the early data we had. That was the month we were not going to be able to pay our server bills any more. Bobby had a job that was paying for the server bills at the time. And it just got too expensive, so the timing was awesome. My dad didn’t want to pay for disappearing photos any more.

Q: So what’s the pressure on you now, now that you’ve had these investments? What are the paths for revenue?

A: Going forward there are lots of different revenue models. One we talk about is in-app transactions (selling extra content or features within the Snapchat app) because we don’t have to build a sales team to make cool things that people want to pay for.

Q: Are you still living at your dad’s?

A: Yes.

Q: How long will that be for?

A: Until he kicks me out.