Ask HN: What would you like to see in a Testing and Targeting Platform?

I am in the process of developing a platform for enabling testing (like Google Website Optimizer) and a (on-site behavioral) targeting (like magnify360) platform. By testing, I mean tools which enable split and multivariate testing of different aspects of the website and landing page. By targeting, I mean a platform which enables you to target your visitor based on (user-defined) segments they belong to. For example, you might want to show a visitor visiting at noon from belonging to a specific city different content (and offers) than a visitor arriving at your website at midnight through a display banner ad. My platform would make this kind of targeting super-easy. What would you like to see in the testing and targeting platform that I am developing?