[borgchick]

I think it isn't so much about what traffic to a static site will do to a server, but rather what the experience is for the end user. The tie in to CDNs help reduce load time for your end user.

[mvn9]

Yet web-apps are made to not be bothered by load-times. Web-apps are cached by the browser. Once downloaded, startup-time should be instantly.

And downloads shouldn't take too long. Basic 1Gbit connections give you 100Mbyte per second, 10M per 100mils. A landing page should be doable in 10M, and then there is at least one second left to load the rest of the page before the user can react and make a choice.

[amenod]

The problem is more about latency, not so much bandwidth. Also, not everyone has a good connection.

Cache only works the second time the user comes to your page. By definition, every user will experience slow loading the first time.

That said, it probably depends on your use case if it is worth bothering with a CDN or not.

[thomaslord]

In the case you mentioned (top of HN with 10,000 visitors), each user would be loading the full webapp for the first time, so I think caching would be mostly irrelevant.