Jobs understood sales in a way that no one else running these tech demos/keynotes seem to. Specifically "show, don't tell."

Look at the MacBook Air launch. Jobs didn't have to say anything about how thin it was, or list product dimensions on a spec sheet. He just pulled it out of an envelope.

Likewise with the iPod. "1,000 songs in your pocket" not "It has a real hard drive with 5GB of storage."