Many web workers, having tasted of the A/B apple, can no longer imagine operating in any other environment. Indeed, they begin to look with pity on the offline world, a terrifying place where each of us possesses only one life to live rather than two (or more) in parallel. “There’s this grilled cheese place down the street,” says Jim Kingsbury, marketing VP at One Kings Lane. “They can’t test anything. Should they price the sandwich at $6 or $6.50? What should be at the top of the menu? Those are purely intuitive choices that they have to make.” At one Silicon Valley office, I overheard an employee complain that dating can’t be A/B tested; an online profile can, to be sure, but once you’re in a relationship with a specific person, 100 percent of the “traffic” is on the line with every decision.

The testable web is so much safer. No choices are hard, and no introspection is necessary. Why is B better than A? Who can say? At the end of the workday, we can only shrug: We went with B. We don’t know why. It just works.