[martinald]

I've always wondered that, and is it an inherent 'flaw' with social media platforms, and FB just got so big that the coming decline will be just as catastrophic as MySpace and Friendster, but from a much greater height?

FB has obviously made very very smart acquisitions in WhatsApp and Instagram. I get the feeling these were primarily made because of the excellent data they had through their VPN app tracking service (as you could see the hypergrowth in real time and know exactly who to pick and how aggressively to go after). I'm sure they have or are working very hard on some alternative to this (maybe buy metadata off ISPs or become a network/transit carrier in their own right so they can see the IPs where stuff is going?).

But I do wonder if all social networks just are fads. You have a problem that as the network gets bigger, it starts becoming less interesting to you. Your social circles start overlapping (you don't want to post anything because it may offend someone, coworkers, grandparents, children), which stops everyone posting, which causes the whole thing to grind to a halt and become less interesting.