I think Sam made a really good point ("You are not necessarily testing for the right things."). In order for A/B testing to be useful, you have to be testing for the right things, but you also have to already have the right things there. Testing the difference between a "Buy now" button and a "Buy this now" button is useless if your web site is trying to sell cow's blood and it is marketed to vegans. It seems like Bill Murray's premise was flawed: He was offering a product (his heart/love/companionship) to someone who did not want it. Through A/B testing, he was able to maximize the enjoyment of her experience in "the store" (the date), but when the time came for a buy-or-fly decision, she flew because she was not interested in the first place. Which is where Jaryl's point comes in - A/B testing isn't about grabbing a specific person (that's what sales calls are for!), it's about making your website more friendly/more usable/more in tune to what the larger number of people are looking for.