http://www.stevesouders.com/blog/2012/02/10/the-performance-golden-rule/
90% of time is in the front end. Top 10 sites = 74%, top 10k = 92%, top 50k = 87%.
http://kly.no/posts/2009_12_08__Varnishstat_for_dummies__.html
Great little article on how to make sense of the varnishstat output.
