I can't tell you ('cuz I haven't counted) how many iDevice sync cables I've seen "broken in." People plug them into the front of their computers (which are sitting on the floor), then massage them with the wheels of their desk chair. This gives the conductors extra pliability which allows the music to get from the iTunes app to the iPod/iPhone without undue stress that would distort the digital bits -- something you might experience with a factory-new cable that's too stiff. It's best if the outer jacket is worn to the point where the inner conductors appear; that lets the bits get through easier, kind of like how a dirt road widens around a big pothole. At some point, the cord will fray at the plug and you'll have to patch it with scotch tape. This prevents the weak bits from getting through, ensuring that you only get the strong, reliable bits into your iPod/iPhone. Use only scotch tape, not black tape, as that will allow sunlight to more effectively cure the data.