Are Twitter Referrers The Most Valuable?

The UK Web Focus blog now gets a lot of traffic from the Web site – and even more, which are not recorded, from Twitter clients.  A summary provided by showed that after the top referring Web sites which Google (Reader) and Google (search engine).

But is traffic from Twitter more valuable than traffic from Google search?  After all a Twitter link reflect an individual’s decision to tweet a link, which may provide some form of endorsement for the content, whereas traffic from Google simply reflects Google algorithms.