The "ipod" and "ipod Touch" were the reason the iPhone was successful. The speed and reaction time was important too - but I wouldn't call it a "killer feature"

The "ipod" and "ipod Touch" were the reason the iPhone was successful. The speed and reaction time was important too - but I wouldn't call it a "killer feature" - it was necessary because phones weren't slow - actually there was nothing particularly slow about about the RAZR. I don't understand the comparison.