@Joe: Thank you for the insight about cached files. For some reason, I don’t feel the video has bad sound quality. It sounds fine for me. Maybe it’s just my computer .

Yes, they are (unless you’re sending silly headers). However, most visitors won’t have a primed cache. Whenever you get a big traffic spike from social bookmarking sites most people will be first time visitors and usually they won’t check out your other articles.

But even regulars will have to download these files over and over again. The reason for this is pretty simple: The caches are just way too small. Often it doesn’t even last for a single day.

Basically caching only helps those visitors who read a few articles in one go. Apart from that there isn’t much of a difference. If you got a lot of regulars it maaaaaybe saves about 10%, but that’s about it.

Gzip on the other hand can peel up to 50% of a given page. That’s a pretty big improvement – even more so if you get flooded by hits.

@video

Worst sound quality ever. It almost made my ears bleed. I’d to stop the video after a few seconds.

@Razvan: I concur. They have been out for a while. The main idea of this post is to express these ideas to those who do not know them.

You could also point the jquery reference to Google’s repository. This way, the user has browsed a site that also has this link, it can safely pull it from the cache.