Some Actual Numbers
Firefox has some very good web developer tools. Here's a brief summary of what happens when the article web page is loaded: All sizes are in uncompressed form with an empty cache.
HTML: 16 requests, 312.91 KB, 22.41 sec
CSS: 2 requests, 72.37 KB, 0.35s
JS: 44 requests, 1,564.87 KB, 14.48s
Images: 124 requests, 1,024.60 KB, 20.45s
Flash (I don't have Flash installed): 4 requests, 0 KB, 2.75s
Other: 4 requests, 0 KB, 0.01s
Of the HTML, here are the top domains in terms of size along with transfer time:
Twitter 50.16KB 0.117s
Facebook 62.54 KB 0.343s
theregister 67.34 KB 0.208s
For the images, the slowest were from the following domains:
cs.meltdsp.com 0.34KB 5.110s
pixel.eversttech.net 0KB 5.100s
cm.dpclk.com 0KB 10.096s
Here's the thing that nobody seems to want to admit. Loading a web page from The Register isn't the slow part. That is very fast. It's also not very big. The problem is the ad networks. There are multiple ad bids, ads, tracking cookies and pixels, and other crap being loaded, often taking a very long time to do so (e.g 5 to 10 seconds each in several cases).
Fiddling with The Register's web page isn't going to do anything significant. For Christ's sake, Twitter and Facebook load as much HTML to do their tracking buttons as El Reg does to display the actual article! And there's roughly 3 dozen other parties all loading their crap, very slowly, into the page.
Fiddling with the size of the images won't help either. Many of them seem to be used as tracking elements by the ad networks, and even very tiny ones take forever to load if they come from an ad network rather than The Register.
The real problem is that ads are served from third party networks, and those ad networks don't care if The Register is slow, it's not their site after all. Instead, they spaff loads of crap into the page, very, very slowly.
The real solution isn't going to be fiddling with the margins. It's going to require restructuring the ad business in order to put the content publishers in control so they can optimise the entire process, just like they do in physical print publishing. I'm not sure how to do that, but I don't see any other way.