This thought started with a Quora question – what is still missing in social networks – I believe it is the category-domain knowledge based discussion groups. Forums today do this, but they are very hard to find, and its hard to compare which/where is the best place for me to make my contribution.
Twitter is too ephemeral and length restriction make it impossible to have a meaningful discussion.
Facebook is best for friends & family sharing – its not a platform for meaningful discussion about a specific topic.
Quora may have some elements of what I’m looking for, but I have a hard time seeing how it will evolve beyond Silicon Valley.
So that leaves an easier way to find and participate in category-domain knowledge based discussions where it doesn’t matter so much who you are, or who you know, but what you know.