Very cool technology demo, but I can't think of any scenario where you'd actually need this "realtimeness". I'm constantly annoyed by the 24h you have to wait for google analytics, though.
The original site, Gilt Group, is a clothing sales store which has sales which start at 12pm EST. Frequently things will sell out within scarse minutes of the start. I imagine having your stats update 20 times/sec is extremely interesting (and exciting) for that kind of application.
It's for the Hollywood-created movie star webmasters of the future! After all, in the movies, everything must scroll incessantly.
Kidding aside, it feels more useful if the rate of usage is slightly less than that in the demo... Seeing hits pop up in real-time definitely has a certain appeal!