Final answer:
An Administered vertical marketing system is where independent channel members cooperate due to the influence of a dominant member.
Step-by-step explanation:
The type of vertical marketing system where channel members remain independent but voluntarily work together due to the power of a single channel member is known as an Administered vertical marketing system. This system is characterized by coordination and integration of activities through a central dominant member of the channel, rather than through ownership (Corporate vertical marketing system) or contractual agreements (Contractual vertical marketing system).
The conventional marketing system is a more traditional approach, with each member of the channel working independently.