Karly Domb Sadof/AP Photo

The smartphone photo sharing app Instagramwas an instant hit when it debuted in 2010. Now, two years later, the app has quickly become the most popular way that phone users share pictures, and may soon become the most popular means to share photos in any way.

When Superstorm Sandy hit the East Coast last week, many people reached for their phones to document the aftermath. Most of them, it seems, used Instagram to snap the photo.

"Sandy was a really interesting event for us," Systrom said at the Nov. 5 GigaOM conference in San Francisco. "Sandy was the single largest event captured on Instagram - and the largest event captured on cellphones ever."

According to Systrom, nearly one million Instagram photos were uploaded with the hashtag #Sandy.

That means Instagram is much more than just a way to show off to your friends. Users, Systrom says, are now updating their accounts to document important events like Sandy in what amounts to participation in the event. Instead of passive documentation, Instagram users are communicating with photos and making their Instagram experience more than just about consumption.

That conversation with photos is also about to get even easier, as the smartphone-based app expands onto the Web. The company, which was purchased by Facebook in the spring of 2012 for nearly $1 billion, is rolling out Instagram profiles, complete with user bios and photo streams of recent uploads.

According to a post on the Instagram blog, Web profiles will be rolled out "over the next few days" in a move that is sure to open the platform up to even more users.