I love the idea... unfortunately something is seriously wrong with their website. They're selling fonts you can use on other websites. I'd expect that they know a lot about fonts - yet, when you look at their own source:
font-family:arial,sans-serif;
Why don't they buy at least one really high quality font from (for example) Linotype? Not even for reselling, but for use on their own website - to show the difference it can make... Why do they try to sell fonts for websites, but don't try to blow my mind by using one of ITCs, or Vialog, or something else for their own main text.
I meant the normal body text to be honest. Instead of showing off with one frame, why not typeset the whole page in one of the fonts? I couldn't find anything both toned down and "different" in there, but this might come close: http://typekit.com/fonts/392 Give it more spacing and you could use it for "normal" text (or even http://typekit.com/fonts/129 if they want to stay with web2.0-ish sans)
Probably because on Windows most of the fonts they have available would look blurry at less than 18px tall. This is due to the way font-hinting and anti-aliasing works (at least in Vista and XP).
i'm not a designer, so i'm obviously out of the loop. still curious about what's going on, though. thus: how much difference do fonts make? any a/b tests? any qualitative urls you can recommend that will blow my mind? keep in mind i use a mac...windows and buttons and fonts already look pretty.