Instagram - the history of half a billion

The five hundred million club, a club that by far surpasses the very ordinary and not nearly as auspicious hundy club. One of which Instagram is now a gold star member.

Half a billion users calls for an explanation; how did the photo sharing app actually come to be?

Well, it all started when Kevin met Mike. Much like when Harry met Sally - a perfect match but minus the romantic plot line.

Launched in October 2010 as a free mobile app, Instagram became an immediate success and, within two months, there were already 1 million global users.

Just one year later, co-founders Kevin Systrom and Mike Krieger were honoured with spots on Fortunes 40 under 40 and Business Insider's 25 under 25 lists.

Two years later and the app had almost 80 million users, an iPhone app of the year award under its belt, and a new owner - Facebook.

Facebook acquired Instagram for one billion dollars in April 2012, a move that Systrom said at the time was imperative to changing the way everyone communicates.

Fast forward three years, Instagram now has half a billion monthly active users and according to a recent Facebook post, Mark Zuckerberg couldn't be prouder.

"More than 500 million people now use Instagram every month -- and 300 million every day. The Instagram community has more than doubled over the past two years. This is a tribute to Kevin Systrom and Mike Krieger's vision, and to people everywhere who have opened a window into their world -- from big events to everyday moments," says Zuckerberg.

"Thanks for making Instagram such a beautiful place."