http://www.google.com/trends?q=vampires,+werewolves Clearly programmers are more popular. ;)

Yikes, you guys are taking this too seriously. Groundhog Day is an analogy for Jeff's thoughts on A/B testing, not evidence that led him to his conclusions. I think the biggest problem with A/B testing is that people who want it don't understand why they want it. What are they testing? What do they hope to accomplish? What will they do with the data they get? All they know is that such-and-such company did A/B testing and increased sales 0.01% so they want it too. Without a plan of action, any tool will fail.