my idea is, that Spotify could at something similar to the Family Plan. Something, where you can invite friends, so your friends, with another address can get cheaper Premium Features too.
But obviously, it should be more expensive like 25-30€, so 6 people would pay 4-5€. Like a new subscription, but dontd forget to make it easy to upgrade feom Premium/ Family Subscription to the Friends Subscription.
What do you think? I would buy it instantly.
Updated on 2018-11-21
A similar idea has also been suggested here:
Please vote for it, and add a comment there, so it may be considered. Any update on the matter should be posted there.
For more info on how the Ideas Board works, click here. :)