A Quora snapshot; on the social graph dimension, note that Quora was co-founded by former Facebook CTO Adam D’Angelo (check the link below for the other six TechCrunch technologies)
Quora Will Have Its Twitter Moment: Social Q&A site Quora may be the current darling of Silicon Valley, but not a lot of people beyond the insular tech startup world actually use it yet. That will start to change in 2011, which I believe will be the year Quora has its Twitter moment and start to really take off. Quora represents a bigger technology trend, which is the layering of an interest graph on top of people’s social graph. On Quora, you can follow not only people, but topics and questions. It defines the world by your interests, not just the people you may know or admire. This is a powerful concept and is not limited to Quora (both Twitter and Facebook also want to own the interest graph), but Quora is designed from the ground up to expose and help you explore your interests. It is addictive, and as it reaches a critical mass of early users, this will be the year it emerges from its shell much like Twitter did in 2007.