We all know that one of the top guidelines from YSlow is to implement a CDN when possible. We just implemented this for all of our sites! We then ran some simulated traffic tests against our site. What an improvement! We already had high marks from YSlow on our site this was one of the last steps needed to get almost all As from YSlow. Bottom line - Content Distribution Networks are super easy to implement and offer a significant performance improvements for any web-site. A cheap way of doing CDN is to simply host two sites on the same server, the primary site and cdn.example.com. This will load-distribute the content and increase the responsiveness of the site. Hopefully the server used has enough resources to handle the traffic load. A better option is to use a secondary server. Amazon Web Services is also introducing a CDN system soon.