Yesterday, mobile darling Instagram launched its Android app and snared one million downloads in 24 hours. The photo-based social juggernaut already boasts 30 million users who pour 5 million photos into the network every day – and with half of all smartphone users in the U.S. now using Android, don’t expect Instagram’s growth to stall. Instead, it’ll be how the company handles its growth spurt that could affect the future of its success.

The following is a conversation we had with co-founder and CEO Kevin Systrom last spring that’s gone unpublished until now.

(MORE: Camera Awesome Adds Instagram Support, Loses One Cool Feature)

TIME: So you were really told at the beginning that a photo sharing app couldn’t be successful?

Kevin Systrom: When we launched, photo sharing was not the thing people thought was cool. In fact, I remember being told while we were working on the idea that photo sharing was dead, that it wasn’t exciting. I actually think people kind of wrote it off until they saw what kind of growth can happen on a photo-based social network. That changed a lot of minds, including other investors and folks who decided to enter the space as well.

TIME: Some startups dig their heels in and say they’ll never sell out. Where do you guys stand? Obviously, at some point you’ve got to make money. Are you under a lot of pressure to monetize?

KS: It’s not really on the top of our minds right now. We’re much more focused on scaling the product and building the team than we are trying to sell an app for $.99.

I think people said the same of search back in the day: “Well, this is cool, but how do you make money off of it? I think that’s the perennial question in businesses that invent business models. Traditional businesses can say, “We’re going to sell widgets to people and it will make X amount of profit.” But new business models are hard.

It’s interesting to talk about it because we question it now, but the whole reason we’re in this is to invent a new business model. And if you’re going to do that, your market needs to be very, very large. I believe photos is one of the underlying things in every social network that becomes successful. We can be very large because of that and then find very interesting ways to make money. But now, we’re focused on growth.

TIME: Do you have any plans to build Instagram out over the Web?

KS: We are fully sold on the fact that if we’re going to do big, meaningful stuff we need to take on networks. We believe mobile is that. The iPhone is the first time I felt like mobile really had a chance to scale hundreds of millions of people and be a platform where you can build on that platform. There’s no coincidence that we launched when iPhone 4 launched with its revamped camera. That was not a coincidence at all. It’s the right time for us.

You can’t take a desktop experience and shove it into a 3-by-4-in screen. It’s a very different behavior pattern. It’s a very different browse pattern. 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.

TIME: You haven’t won over the entire professional photography community yet. Some have been pretty vocal about it, too. How do you deal with that?

KS: I didn’t start this to be a photo app. It was about communicating visually. Those are two very different things. A photo app is a utility. It’s like comparing Twitter to Microsoft Word. If you want to be an author, you’re not always going to constrain yourself to 140 characters.

TIME: You’ve got a background in photography yourself, right?

KS: Yeah, I grew up as a photo nut. Every Christmas I would get a new camera. It’s a huge part of my life.

When I studied abroad my teacher set what I do know in motion by saying, “Give me that camera of yours.” He took my camera away and gave me a little, plastic camera. I was studying in Florence at the time and he told me that I wasn’t allowed to use my camera for the rest of the class. I had to use this plastic camera with a terrible lens. He said I was too focused on sharpness and “I feel like you’re more artsy than that.” He said, “I want you to use this Holga,” this plastic camera with a plastic lens that had this cult following in the ’80s and ’90. I was blown away by what it could do to photos. My photography teacher was totally right. I was too focused on being meticulous with these really beautiful, complex architectural shots. It helps to see the world through a different lens and that’s what we wanted to do with Instagram. We wanted to give everyone the same feeling of discovering the world around you through a different lens.

Read more: http://techland.time.com/2012/04/04/kevin-systrom-interview/?iid=tl-main-lede#ixzz1rG2HcpY9