John Gruber, commenting on Clay Christensen:
The iPhone is not and never was a phone. It is a pocket-sized computer that obviates the phone. The iPhone is to cell phones what the Mac was to typewriters.
Clay Christensen was wrong when he predicted the iPhone would fail. He thought there was no way it would disrupt the mobile industry. But it didn’t disrupt mobile, it disrupted the mobile computing job to be done.
Sometimes, even if we take into consideration our products’ jobs to be done, we may be addressing the wrong job.