• by Gavin O'Malley , Staff Writer @mp_gavin, September 24, 2015

Congratulations are in order for Instagram (and Facebook, whose $1 billion Instagram buy is now looking like the biggest steal since “The Scream” went missing.) Instagram has officially surpassed 400 million users, and is fast on its way to half a billion.

And mobile deserves all the credit. Well, maybe not all of it, but the site’s ascension would certainly have been improbable without the simultaneous mobile boom.

Beyond its supremely simple and mobile-friendly design -- and reluctance to offer many of its most popular features on the boring old Web -- Instagram tapped into what have become our favorite mobile behaviors: taking pictures, sharing them with friends, and browsing the shared work of complete strangers.

And, as silly as the selfie is, it has proven to be a powerful force, thanks to the universality of visual storytelling and its ability to transcend borders and language barriers.

This trend has fostered rapid adoption of Instagram around the world. Indeed, by its own count, more than 75% of users now live outside of the United States.

Clearly, people also love looking at the world through rose-colored glasses, which Instagram and its famous filters have made painfully easy.

Between its big numbers and solid business model, Instagram is likely to survive the inevitable exodus of cool, young users. (Yes, as with all social networks, this fate is written in stone.)

As Facebook has proven, networks need not live and die at the hand of the young. Like its parent company, Instagram is now approaching a scale in which demographic shifts mean less and less.  

Instagram is showing itself to be the network for our mobile age. Until a new channel takes shape (Facebook is obviously betting on virtual reality headsets), its position now seems secure.

This column was previously published in Moblog on September 23, 2015.