I been an advocate of conservative valuations but, in this case, I highly agree with the number proposed.<p>Quora is much better than all its comparable companies (eHow, Mahalo, etc...) in every possible sense: community, technology, founding team, etc. Traffic is very strong, it displays strong social integration tools and has managed grow very impressively.<p>On a side note, I expect Quora to move into the mainstream with much less friction than Reddit or Askolo. Being more design and experience oriented, Quora has the upper hand here. I hope Quora's team realizes and exceeds this valuation.