I'm agreed you can't test everything -- but that's a limitation imposed by scarce resources (developer time, money, experimental subjects), not by the technolog

I'm agreed you can't test everything -- but that's a limitation imposed by scarce resources (developer time, money, experimental subjects), not by the technology per se. And I'm agreed that trying to enumerate the space of possible designs is a mostly futile effort for most businesses. However, if we take a broader view you can see a market as an experiment. Different companies in a competitive space (e.g. MP3 players before the iPod's dominance, A/B testing software now) choose particular feature sets, price points, and so on. Some are successful, and some aren't. It's difficult to learn from these experiments what contributes to success, as so many factors are mingled together and there is no systematic exploration of the space. As such, a common response is to assign success to the intangible -- "vision" or "genius" -- but I think this is taking the easy way out. Larger companies certainly use the market as a system o judge companies to acquire, and then often get burned when they fail to understand and maintain what brought about the acquired company's success.