I'm a little confused by the public folders in Exchange 2013. The documentation from Microsoft makes it sound like the hierarchy of the public folder is held always in the master public folder mailbox and the content is held in the individual (or whichever public folder mailbox the user is assigned to).
But what we have seen is everything is held in the master. You can map a user to a secondary public folder mailbox and add data but the size of the mailbox doesn't grow.. the master public folder mailbox size grows.
So is the hierarchy AND the data always stored in the master? If so what exactly is the point of creating secondary mailboxes?