What does this mean?

"Share Unlocked Official Content with Others For up to 3 campaigns"

Does it mean that you can have up to three campaigns going at the same time that can share your content, or does it mean that the benefits run out after you have finished your third campaign?

If it is the latter, then I will pass on the subscription. I don't like things that run out.
If it is the former, then I could probably work with that.

I believe it to be the former, but remember that the subscription itself will run out. 

True, but at least I could buy it for a year at a time.

I definitely want a definitive answer to this before I buy it though. Even though it looks like the answer to this is the former.

Hi, I am not sure if I understood the question, but here how the Master Tier works:

You have 3 campaign slots to the share the purchased content, whether you are a player or the DM. You can use these 3 slots as you want (not all at the same time) and you can enable and disable the sharing anytime you like. There is no expiration for the campaign slots, aside, of course, for the subscription itself.

Quote from Stormknight >>

Just to confirm for you 100% - you are allowed as many campaigns as you like.

With a Master Subscription, at any time, you can designate up to 3 of those campaigns as having "content sharing enabled"

You can change which campaigns they are as many times as you like and there is no expiry, as long as you have a Master Subscription.

What happens to the characters in a campaign when you turn off sharing?