Won't this approach have a FOUC-type experience, where the A/B div disappears after being shown to some users? I think it's cool you're attacking this. I thin

Won't this approach have a FOUC-type experience, where the A/B div disappears after being shown to some users? I think it's cool you're attacking this. I think you should check out Google Web Optimizer (iirc), which will do some of the heavy lifting for you. For example, there's no stickiness here, which I think is a typical best practice.