Huge numbers of users don't really mean that much. Bandwidth is the main cost, but that's kept low by having a simple design. Serving the same content several

Huge numbers of users don't really mean that much. Bandwidth is the main cost, but that's kept low by having a simple design. Serving the same content several times in a row requires very few resources - remember, reads far outnumber writes, so even dynamic comment pages will be served many times in between changes. 5.5 million page views a day is only 64 views a second, which isn't that hard to serve. As for the writes, as long as significant serialization is avoided, it is a non-issue. (The vast majority of websites could easily be designed to be as efficient.)