Also, when asked by Mossberg why Apple does not constantly churn out top hits (using a music metaphor) it apparently didn't occur to him to reject the premise of the question. The obvious answer would have been "I disagree, Apple continues to deliver a constant stream of big hits every single year. What you're really asking is how often do we get to invent entirely new genres, and I assure you you have seen nothing yet. At the same time you have to keep in mind that innovation is not a mechanical process occurring at regular intervals."