I was pulling my visitor stats for the last 6 months at SEOmoz (Aug 2005 - Present) and found this remarkable bit of data worthy of interest:

Top 10 Referring Domains:

direct access or bookmark - 44.08%
https://slashdot.org - 9.75%
https://moz.com - 6.49%
https://www.google.com - 4.84%
https://del.icio.us - 2.27%
https://www.bloglines.com - 2.02%
https://www.seocompany.ca - 1.55%
https://blog.searchenginewatch.com - 0.75%
https://www.lifehacker.com - 0.73%
https://search.yahoo.com - 0.63%

Pretty interesting that a site which has ranked well for a large number of long tail terms and (more recently) top 10 for several competitive terms has less than 10% of its total traffic delivered via search...

It makes for a good case study on how natural link building is far more valuable than just SE value - those links serve up some very lovely visitor numbers, especially when taken in concert. Anyone else have a site that gets less than 10% of traffic from search? It seems ironic for an SEO firm...