Anecdotal evidence: I had never messed with Instragram until I got a girlfriend whose peer group used that exclusively over Facebook. These are all in the 28-32 age range. It seems they were all eager to use a system that just focused on sharing photos and didn't want all the 'bloat' associated with Facebook. In addition to preferring the focus on photosharing, there was a sense of just wanting to be back on a network where they just dealt with the few people they cared about.
Obviously Instagram falls under the Facebook umbrella, but it did serve as a wake up call to me about there possibly being a group of young professionals that is more than willing to completely ditch Facebook proper for something that better fits their social networking goals.
Obviously Instagram falls under the Facebook umbrella, but it did serve as a wake up call to me about there possibly being a group of young professionals that is more than willing to completely ditch Facebook proper for something that better fits their social networking goals.