> most of the value in social media is due to the network effect

Global network effects require consolidation. But there are many local network effects that add value with less scale.

In the real world, these local networks emerge as friend circles, interest groups, block associations, companies and industry networks. These local networks are either subsets of or correlated with the global network. But they produce value relatively independently of it.

Starting such a social media company today is hard because surviving amidst Facebook is hard. (See Snapchat, which could be considered, at its start, a local network of a certain age group.) Portability lowers this barrier for new entrants.