Originally the “don’t bother” trilogy said if you haven’t talked to at least 25 poor customers before you start, if it doesn’t pay for itself three times in the first year, and if you can’t sell a million of them, don’t bother. That’s provided a very useful challenge to designers. As I’ve progressed in the past few years, those basic principles have become even more radical. So now I don’t do anything unless it’s at least 100 million customers.
