Social networking is based on communication. If we can say it is some kind of segment, given the market size does not change rapidly, any alternative emergence in communication leads to potential losing market share for existing players. Snapchat as a way to communicate is definitely grabbing the market share now. So as long as they can grow well, it will become the true next big thing(if they are not one already). I think the market share of communication point of view could provide some help to understand this. I found this out not long ago and believe this is one of the key dimensions to know the landscape better. I have not given any more deep thoughts on this yet.