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 wou

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.