I am looking at getting DDB with the three core books and a campaign book when it releases. I also plan on getting the Master subscription. Without sharing my account info can i pass the "DM" role for a given campaign to one of my "players" or can I be the only "DM" within my account? I hope I am asking this clearly but let me know if I need to explain this better.

Yes the owner of the Master Tier can decide which "guest" is going to be the DM.

Excellent! Thanks for the info. Sorry if this was posted in another thread.