I want to know the answer to the following question:
What iPod feature allowed for USB connections with the device?
All the background I'm provided with is that "As of the first-generation iPod Nano and the fifth-generation iPod Classic, Apple discontinued using FireWire for data transfer (while still allowing for use of FireWire to charge the device) in an attempt to reduce cost and form factor.". Is that enough to answer the question?
Answer: no