Joseph Valente:

Essentially it turns around Apple’s complete willingness to destroy its own revenues. It built a phone that destroyed it’s major source of revenue, the iPod. It built Macbook Airs that have now disrupted another major source of revenue, their Macbook Pros. It built the iPad, which is already beginning to disrupt the Macbook itself.

Apple also killed off the iPod mini at the height of its popularity and introduced the iPod nano in its place. That completely disrupted the competition because at that time they were all trying to copy the mini.