Photo sharing is something that everyone is trying desperately to solve. When I open the G+ app on my iPhone it wants to upload all the new photos it can find on the phone. I would imagine the Facebook app does the same thing, but I don't know. The OS has cloud storage for photos baked in. When I plug the phone into my computer, Dropbox wants to automatically find and upload the photos.

Everyone is trying to get into this, and for good reason, I think.

My family is filled with people that always have access to a camera and to the internet via their phone. We're spread out geographically and don't get to see each other very often. There is a HUGE opportunity to bring us closer together that would be greatly valuable to us. I would love it if part of our daily routine included looking at all of the photos anyone in the family has taken in the last day.

There are lots of solutions for us to do this, but for whatever reason, nothing has taken hold. Maybe everything is too manual, or maybe social networks are still focused too much on the browser and not enough on mobile. But for whatever reason, it's not happening for us. I suspect we are not alone and I think the explosion of people trying to get me to buy into putting my photos on their free service is indicative of this.

It's not necessarily that Instagram would become a viable competing alternative to Facebook on its own. Rather, it seems reasonable to imagine that Facebook would be concerned about the widespread adoption of third-party, cross-platform social infrastructure, as provided by Instagram.

Instagram, in providing a photo sharing experience (at least) on par with Facebook's, spanning multiple "social platforms", facilitates user migration across these platforms. In the current context, any user migration between social platforms would (almost) inevitably dilute Facebook's share of user-time.

Thus, it seems reasonable for Facebook to acquire this possible avenue of departure and generally maintain its current state while guiding future evolution of Instagram's product to subtly guide the flow of users along "Instagram Avenue" towards Facebook, rather than in its current unbiased direction.

Though useful from a business perspective, this sort of defensive acquisition is discouraging to me. I would prefer to see the evolution of "social" in general towards an open protocol for maintaining the actual user<->user graph structure and piping of information along it, with a loose confederation of services such as Instagram providing the content hosting/delivery. This would decentralize control of people's social graphs, with control being restricted to subsets of the shared content and its flow over the graph, rather than the actual graph structure itself. I.e. market-driven services such as Instagram would compete to control portions of the infrastructure implementing this new construction, which one might call the "world wide (social) web".

TLDR: Facebook's purchase of Instagram permits them to simultaneously reduce the instantaneous rate of user migration across social platforms while preventing the emergence of a competitive open social platform/protocol, the evolution of which would be greatly facilitated by the prior existence of third-party social content infrastructure such as Instagram, which reduces the size of the "chicken and egg" problem confronting any attempt at an open platform.

But that is how Facebook won the opening salvos of the ongoing social media competition. They had easy to use photo sharing wrapped in the veneer of social commenting so people could share photos and interact with each other (about the photos) easily. As an anecdote, this was the compelling reason most everyone I knew migrated from Xanga over to FB--they could share all their photos and interact with their friends in one spot.

Instagram took the whole photo sharing idea and ran with it to the next level to include multi-platform sharing and picture editing. Put a social wrapper of some sort around that, and you're back where FB was when it took off several years ago--exception being you have BETTER photos.

TL;DR Photos win the social networking game. Good photo sharing + easy to use social == winning formula, see FB's early years and reasons for adoption.

Moving photos from one service to another is doable, but it requires a LOT of effort from the average user (relatively speaking). Even if another company made an "import instagram photos to service X", the perceived effort of moving would prevent most users from finding such an import feature and making the move.

Photos are a pretty solid natural barrier that could protect Instagram while they made that long trek.

That being said, stickiness and perceived lock-in with photos doesn't make the trek any less arduous.