During his company’s quarterly earnings call today, Facebook co-founder and CEO Mark Zuckerberg discussed how Instagram will be monetized. The answer isn’t too surprising: there is a big expectation for the app to one day be profititable, and advertising will be the name of the game.

“Kevin [Systrom] has always been clear that we’re building Instagram to be a business,” Zuckerberg said. “We expect over time to generate a lot of profit from it. We think the right focus for now is to continue increasing the footprint of Instagram and, when the right time comes, we’ll think about advertising.”

Instagram as have been a long-time coming, even before Facebook acquired the company last year. Yet Zuckerberg’s statement makes it quite clear what’s in the cards for the popular photo (and now video) app, without actually revealing a timeframe.

While most users aren’t particularly fond of ads, they tolerate them as the result often means a free service. In fact, when it comes to social networks, the advertising model is the only one that has been consistently successful.

Although there has been quite a bit of talk about paying a fee to access a social network, such as App.net, nobody has managed to scale it. We would be very surprised for Facebook to start charging Instagram users, even for premium features, as the app is already the leader in its category.

In fact, Instagram’s growth has been phenomenal, even with Facebook as a parent company. Last month, it announced 16 billion photos shared, 1 billion likes, and 130 million monthly active users. That’s right: Instagram already has more than 10 percent of Facebook’s total userbase.

See also – After launching online profiles, Instagram now lets you view your feed, like photos, and comment on the Web and Instagram turns on ‘Photos of You’ section for everyone, here’s how to control the pictures you’re tagged in

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