In an earlier post I refered to Damon Hart-Davis’ investigation of cloud services because it followed the same path as my own with similar conclusions.
He has now published a fourth part on Amazon Content Delivery Network (CDN). A CDN caches static resources closer to the user. This gives your user a faster browsing experience and can actually reduce your total costs by offloading EC2 CPU and input and output.
In conclusion it works well. The details are here.