Full story below courtesy of [Mashable]

Among Facebook‘s motives for buying Instagram, the photo-sharing app’s success on mobile was clearly a big draw.

In the short year-and-a-half since its launch, Instagram has grown to 30 million users — and did it all without a website.

The app only lives on mobile and, until launching an Android version earlier this month, could only be downloaded on iOS devices. Photos can be uploaded to a user’s Twitter,Facebook, Tumblr and other social presences. However, there’s no database of Instagram photos or even user profiles that can be found on the web. While independent developers have created websites to accompany the app, there is no Instagram interface for users to access online. It’s a world that exists only in the palm of your hand; It’s mobile-only.

For those trying to make sense of that $1 billion price tag, this raises a number of questions. Do you need a website or can a mobile app succeed on its own? Is this a viable strategy for other apps or is Instagram truly an anomaly?

We asked a few mobile experts to share their opinions on Instagram and whether mobile-only is really the next frontier for social networks.