The Group Memberships add-on for Paid Member Subscriptions lets you sell subscriptions to groups of people.
A single person takes care of the billing aspect of the subscription and can invite a number of additional members, depending on the subscription settings, which get access to the same subscription without having to pay again.
Group Memberships are also known as Umbrella Memberships.
Some usage examples for this add-on would be selling Group Memberships to Companies, Families, a School Teacher signing up his/her class etc.
Since the Group Owner is responsible for the billing of the subscription, management of the subscription for multi-member groups is a breeze. If the owner subscription expires every account from the group will expire as well.