That is talking about specs, and it is exactly what the competition did too. Here in the unit "number of songs". Maybe most people at the time couldn't translate GBs into number of songs, but nowadays bandwidth or "surf" is talked about in terms of GBs because it has become familiar through experience.
The iPod had better specs and better design. The original Jobs presentation even puts up a table or 2x2 illustrating how the iPod specs would be superior.
Obviously, one adapts language to audience, but I've never seen a case where this is the real reason for success or failure.