How do people do this?
My obstacle with this point is each CDN would have a different impact in each locale due to the locations of their points of presence, and CDN-ing each resource would a different impact based on the sites that particuar individual had visited.
Measuring it in any useful way in advance of a change would be really hard unless I'm missing a trick, and measuring it in hindsight would require the kind of performance logging that PaaS-level apps don't have access to.
