Yes this swell in page size corresponds very nicely with everyone's favorite cliche, Web 2.0. It is obviously not a coincidence. More features and interactivity is going to be mean more initial download, which is the very coarse metric being used here. What may have been four web pages may now be one Ajax-ified one, whose weight is three times as much. More interesting tidbits.
- Average page weight: 310 KB
- Average total JS: 68 KB
- Average # of external JS files: 7
- Average # of unique external JS files: 6 (gotta love duplicates!)
- Average total CSS: 15 KB
- Average total image pixels: 49,144
- Percentage of HTTP requests dedicated to images: 75%
That last stat is not really as bad as it seems. Images are (can be) loaded in parallel. There is a limit of connections per domain, however (generally two.) A common trick is if you have to load 20 images all from the same server, trick the browser. Make the first two images from images0.mydomain.com, the next two from images1.mydomain.com, etc. Obviously images0 and images1 point to the same IP address, but you get the gist. The browser will load all of the images in parallel (or close to it.) The one disadvantage is you can lose some browser caching. The browser will think that http://images0.mydomain.com/foo.gif and http://images1.mydomain.com/foo.gif are different images.
The other interesting thing talked about in the article, is that broadband speed has more than kept up with page bloat, err Web 2.0. However, not everybody has broadband, and you are basically suffering now more than ever if you do not. These studies are only talking about home users, what about mobile phones? If you are an iPhone user on EDGE, how do you like 310 KB pages?
It seems likely that we will start seeing "lite" versions of websites in the future. We kind of see this for mobile devices, i.e. m.mydomain.com or mobile.mydomain.com. At some point, will we start directing dial-up users to the lite sites? If you were a dial-up user, how would you feel about that? I'm from the South, so it kind of feels like segregation to me: "equal but separate."