[Animats]

Thinking about it, I like the idea of using automated A/B testing to automatically drive layout optimization. That would be fascinating to watch. Provide the system with a supply of images and copy, maybe 5x as much content as the site shows, and let it optimize for maximum clicks.

Someone could probably get VC funding for that.

[tomadi]

You just described exactly how the Amazon.com homepage works. I think they even published a paper about it.

[Animats]

That's how most ad placement works, but it hasn't been applied to general layout.